mirror of https://github.com/postgres/postgres
index page contents. Satoshi NagayasuREL8_2_STABLE
Bruce Momjian
19 years ago
parent
04912899e7
commit
74924d29fa
@ -0,0 +1,706 @@ |
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/*
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* pgstatindex |
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* |
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* Copyright (c) 2006 Satoshi Nagayasu <nagayasus@nttdata.co.jp> |
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* |
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* Permission to use, copy, modify, and distribute this software and |
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* its documentation for any purpose, without fee, and without a |
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* written agreement is hereby granted, provided that the above |
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* copyright notice and this paragraph and the following two |
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* paragraphs appear in all copies. |
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* |
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT, |
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* INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING |
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* LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS |
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* DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED |
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* OF THE POSSIBILITY OF SUCH DAMAGE. |
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* |
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* THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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* A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS |
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* IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, |
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* SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. |
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*/ |
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#include "postgres.h" |
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#include "fmgr.h" |
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#include "funcapi.h" |
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#include "access/heapam.h" |
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#include "access/itup.h" |
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#include "access/nbtree.h" |
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#include "access/transam.h" |
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#include "catalog/namespace.h" |
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#include "catalog/pg_type.h" |
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#include "utils/builtins.h" |
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#include "utils/inval.h" |
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PG_FUNCTION_INFO_V1(pgstatindex); |
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PG_FUNCTION_INFO_V1(bt_metap); |
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PG_FUNCTION_INFO_V1(bt_page_items); |
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PG_FUNCTION_INFO_V1(bt_page_stats); |
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PG_FUNCTION_INFO_V1(pg_relpages); |
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extern Datum pgstatindex(PG_FUNCTION_ARGS); |
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extern Datum bt_metap(PG_FUNCTION_ARGS); |
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extern Datum bt_page_items(PG_FUNCTION_ARGS); |
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extern Datum bt_page_stats(PG_FUNCTION_ARGS); |
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extern Datum pg_relpages(PG_FUNCTION_ARGS); |
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#define PGSTATINDEX_TYPE "public.pgstatindex_type" |
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#define PGSTATINDEX_NCOLUMNS 10 |
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#define BTMETAP_TYPE "public.bt_metap_type" |
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#define BTMETAP_NCOLUMNS 6 |
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#define BTPAGEITEMS_TYPE "public.bt_page_items_type" |
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#define BTPAGEITEMS_NCOLUMNS 6 |
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#define BTPAGESTATS_TYPE "public.bt_page_stats_type" |
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#define BTPAGESTATS_NCOLUMNS 11 |
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#define IS_INDEX(r) ((r)->rd_rel->relkind == 'i') |
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#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID) |
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#define CHECK_PAGE_OFFSET_RANGE(page, offset) { \ |
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if ( !(FirstOffsetNumber<=(offset) && \
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(offset)<=PageGetMaxOffsetNumber(page)) ) \
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elog(ERROR, "Page offset number out of range."); } |
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#define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \ |
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if ( (blkno)<0 && RelationGetNumberOfBlocks((rel))<=(blkno) ) \
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elog(ERROR, "Block number out of range."); } |
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/* ------------------------------------------------
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* structure for single btree page statistics |
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* ------------------------------------------------ |
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*/ |
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typedef struct BTPageStat |
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{ |
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uint32 blkno; |
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uint32 live_items; |
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uint32 dead_items; |
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uint32 page_size; |
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uint32 max_avail; |
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uint32 free_size; |
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uint32 avg_item_size; |
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uint32 fragments; |
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char type; |
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/* opaque data */ |
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BlockNumber btpo_prev; |
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BlockNumber btpo_next; |
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union |
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{ |
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uint32 level; |
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TransactionId xact; |
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} btpo; |
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uint16 btpo_flags; |
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BTCycleId btpo_cycleid; |
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} BTPageStat; |
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/* ------------------------------------------------
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* A structure for a whole btree index statistics |
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* used by pgstatindex(). |
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* ------------------------------------------------ |
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*/ |
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typedef struct BTIndexStat |
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{ |
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uint32 magic; |
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uint32 version; |
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BlockNumber root_blkno; |
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uint32 level; |
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BlockNumber fastroot; |
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uint32 fastlevel; |
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uint32 live_items; |
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uint32 dead_items; |
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uint32 root_pages; |
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uint32 internal_pages; |
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uint32 leaf_pages; |
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uint32 empty_pages; |
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uint32 deleted_pages; |
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uint32 page_size; |
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uint32 avg_item_size; |
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uint32 max_avail; |
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uint32 free_space; |
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uint32 fragments; |
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} BTIndexStat; |
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/* -------------------------------------------------
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* GetBTPageStatistics() |
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* |
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* Collect statistics of single b-tree leaf page |
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* ------------------------------------------------- |
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*/ |
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static bool |
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GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat) |
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{ |
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Page page = BufferGetPage(buffer); |
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PageHeader phdr = (PageHeader) page; |
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OffsetNumber maxoff = PageGetMaxOffsetNumber(page); |
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BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page); |
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int item_size = 0; |
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int off; |
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stat->blkno = blkno; |
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stat->max_avail = BLCKSZ - (BLCKSZ - phdr->pd_special + SizeOfPageHeaderData); |
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stat->dead_items = stat->live_items = 0; |
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stat->page_size = PageGetPageSize(page); |
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/* page type (flags) */ |
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if (P_ISDELETED(opaque)) |
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{ |
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stat->type = 'd'; |
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return true; |
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} |
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else if (P_IGNORE(opaque)) |
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stat->type = 'e'; |
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else if (P_ISLEAF(opaque)) |
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stat->type = 'l'; |
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else if (P_ISROOT(opaque)) |
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stat->type = 'r'; |
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else |
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stat->type = 'i'; |
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/* btpage opaque data */ |
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stat->btpo_prev = opaque->btpo_prev; |
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stat->btpo_next = opaque->btpo_next; |
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if (P_ISDELETED(opaque)) |
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stat->btpo.xact = opaque->btpo.xact; |
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else |
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stat->btpo.level = opaque->btpo.level; |
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stat->btpo_flags = opaque->btpo_flags; |
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stat->btpo_cycleid = opaque->btpo_cycleid; |
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/*----------------------------------------------
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* If a next leaf is on the previous block, |
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* it means a fragmentation. |
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*---------------------------------------------- |
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*/ |
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stat->fragments = 0; |
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if (stat->type == 'l') |
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{ |
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if (opaque->btpo_next != P_NONE && opaque->btpo_next < blkno) |
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stat->fragments++; |
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} |
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/* count live and dead tuples, and free space */ |
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for (off = FirstOffsetNumber; off <= maxoff; off++) |
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{ |
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IndexTuple itup; |
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ItemId id = PageGetItemId(page, off); |
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itup = (IndexTuple) PageGetItem(page, id); |
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item_size += IndexTupleSize(itup); |
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if (!ItemIdDeleted(id)) |
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stat->live_items++; |
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else |
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stat->dead_items++; |
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} |
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stat->free_size = PageGetFreeSpace(page); |
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if ((stat->live_items + stat->dead_items) > 0) |
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stat->avg_item_size = item_size / (stat->live_items + stat->dead_items); |
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else |
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stat->avg_item_size = 0; |
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return true; |
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} |
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/* ------------------------------------------------------
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* pgstatindex() |
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* |
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* Usage: SELECT * FROM pgstatindex('t1_pkey'); |
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* ------------------------------------------------------ |
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*/ |
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Datum |
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pgstatindex(PG_FUNCTION_ARGS) |
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{ |
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text *relname = PG_GETARG_TEXT_P(0); |
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Relation rel; |
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RangeVar *relrv; |
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Datum result; |
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uint32 nblocks; |
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uint32 blkno; |
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BTIndexStat indexStat; |
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relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname)); |
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rel = relation_openrv(relrv, AccessShareLock); |
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if (!IS_INDEX(rel) || !IS_BTREE(rel)) |
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elog(ERROR, "pgstatindex() can be used only on b-tree index."); |
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/*-------------------
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* Read a metapage |
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*------------------- |
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*/ |
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{ |
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Buffer buffer = ReadBuffer(rel, 0); |
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Page page = BufferGetPage(buffer); |
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BTMetaPageData *metad = BTPageGetMeta(page); |
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indexStat.magic = metad->btm_magic; |
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indexStat.version = metad->btm_version; |
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indexStat.root_blkno = metad->btm_root; |
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indexStat.level = metad->btm_level; |
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indexStat.fastroot = metad->btm_fastroot; |
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indexStat.fastlevel = metad->btm_fastlevel; |
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ReleaseBuffer(buffer); |
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} |
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nblocks = RelationGetNumberOfBlocks(rel); |
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/* -- init stat -- */ |
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indexStat.fragments = 0; |
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indexStat.root_pages = 0; |
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indexStat.leaf_pages = 0; |
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indexStat.internal_pages = 0; |
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indexStat.empty_pages = 0; |
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indexStat.deleted_pages = 0; |
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indexStat.max_avail = 0; |
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indexStat.free_space = 0; |
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/*-----------------------
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* Scan all blocks |
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*----------------------- |
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*/ |
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for (blkno = 1; blkno < nblocks; blkno++) |
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{ |
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Buffer buffer = ReadBuffer(rel, blkno); |
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BTPageStat stat; |
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/* scan one page */ |
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stat.blkno = blkno; |
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GetBTPageStatistics(blkno, buffer, &stat); |
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/*---------------------
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* page status (type) |
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*--------------------- |
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*/ |
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switch (stat.type) |
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{ |
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case 'd': |
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indexStat.deleted_pages++; |
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break; |
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case 'l': |
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indexStat.leaf_pages++; |
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break; |
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case 'i': |
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indexStat.internal_pages++; |
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break; |
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case 'e': |
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indexStat.empty_pages++; |
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break; |
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case 'r': |
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indexStat.root_pages++; |
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break; |
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default: |
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elog(ERROR, "unknown page status."); |
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} |
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/* -- leaf fragmentation -- */ |
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indexStat.fragments += stat.fragments; |
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if (stat.type == 'l') |
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{ |
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indexStat.max_avail += stat.max_avail; |
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indexStat.free_space += stat.free_size; |
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} |
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ReleaseBuffer(buffer); |
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} |
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relation_close(rel, AccessShareLock); |
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/*----------------------------
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* Build a result tuple |
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*---------------------------- |
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*/ |
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{ |
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TupleDesc tupleDesc; |
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int j; |
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char *values[PGSTATINDEX_NCOLUMNS]; |
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HeapTupleData tupleData; |
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HeapTuple tuple = &tupleData; |
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tupleDesc = RelationNameGetTupleDesc(PGSTATINDEX_TYPE); |
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j = 0; |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", indexStat.version); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", indexStat.level); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", (indexStat.root_pages + |
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indexStat.leaf_pages + |
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indexStat.internal_pages + |
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indexStat.deleted_pages + |
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indexStat.empty_pages) * BLCKSZ); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", indexStat.root_blkno); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", indexStat.internal_pages); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", indexStat.leaf_pages); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", indexStat.empty_pages); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", indexStat.deleted_pages); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%.2f", 100.0 - (float) indexStat.free_space / (float) indexStat.max_avail * 100.0); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%.2f", (float) indexStat.fragments / (float) indexStat.leaf_pages * 100.0); |
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tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc), |
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values); |
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result = TupleGetDatum(TupleDescGetSlot(tupleDesc), tuple); |
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} |
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PG_RETURN_DATUM(result); |
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} |
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/* -----------------------------------------------
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* bt_page() |
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* |
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* Usage: SELECT * FROM bt_page('t1_pkey', 0); |
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* ----------------------------------------------- |
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*/ |
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Datum |
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bt_page_stats(PG_FUNCTION_ARGS) |
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{ |
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text *relname = PG_GETARG_TEXT_P(0); |
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uint32 blkno = PG_GETARG_UINT32(1); |
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Buffer buffer; |
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Relation rel; |
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RangeVar *relrv; |
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Datum result; |
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relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname)); |
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rel = relation_openrv(relrv, AccessShareLock); |
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CHECK_RELATION_BLOCK_RANGE(rel, blkno); |
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buffer = ReadBuffer(rel, blkno); |
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if (!IS_INDEX(rel) || !IS_BTREE(rel)) |
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elog(ERROR, "bt_page_stats() can be used only on b-tree index."); |
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if (blkno == 0) |
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elog(ERROR, "Block 0 is a meta page."); |
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{ |
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HeapTuple tuple; |
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TupleDesc tupleDesc; |
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int j; |
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char *values[BTPAGESTATS_NCOLUMNS]; |
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BTPageStat stat; |
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GetBTPageStatistics(blkno, buffer, &stat); |
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tupleDesc = RelationNameGetTupleDesc(BTPAGESTATS_TYPE); |
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j = 0; |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.blkno); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%c", stat.type); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.live_items); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.dead_items); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.avg_item_size); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.page_size); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.free_size); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.btpo_prev); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.btpo_next); |
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values[j] = palloc(32); |
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if (stat.type == 'd') |
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snprintf(values[j++], 32, "%d", stat.btpo.xact); |
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else |
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snprintf(values[j++], 32, "%d", stat.btpo.level); |
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values[j] = palloc(32); |
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snprintf(values[j++], 32, "%d", stat.btpo_flags); |
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tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc), |
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values); |
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result = TupleGetDatum(TupleDescGetSlot(tupleDesc), tuple); |
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} |
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ReleaseBuffer(buffer); |
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relation_close(rel, AccessShareLock); |
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PG_RETURN_DATUM(result); |
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} |
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/*-------------------------------------------------------
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* bt_page_items() |
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* |
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* Get IndexTupleData set in a leaf page |
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* |
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* Usage: SELECT * FROM bt_page_items('t1_pkey', 0); |
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*------------------------------------------------------- |
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*/ |
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/* ---------------------------------------------------
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* data structure for SRF to hold a scan information |
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* --------------------------------------------------- |
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*/ |
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struct user_args |
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{ |
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TupleDesc tupd; |
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Relation rel; |
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Buffer buffer; |
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Page page; |
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uint16 offset; |
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}; |
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Datum |
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bt_page_items(PG_FUNCTION_ARGS) |
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{ |
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text *relname = PG_GETARG_TEXT_P(0); |
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uint32 blkno = PG_GETARG_UINT32(1); |
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RangeVar *relrv; |
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Datum result; |
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char *values[BTPAGEITEMS_NCOLUMNS]; |
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BTPageOpaque opaque; |
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HeapTuple tuple; |
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ItemId id; |
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FuncCallContext *fctx; |
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MemoryContext mctx; |
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struct user_args *uargs = NULL; |
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if (blkno == 0) |
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elog(ERROR, "Block 0 is a meta page."); |
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if (SRF_IS_FIRSTCALL()) |
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{ |
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fctx = SRF_FIRSTCALL_INIT(); |
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mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx); |
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uargs = palloc(sizeof(struct user_args)); |
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uargs->tupd = RelationNameGetTupleDesc(BTPAGEITEMS_TYPE); |
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uargs->offset = FirstOffsetNumber; |
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relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname)); |
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uargs->rel = relation_openrv(relrv, AccessShareLock); |
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CHECK_RELATION_BLOCK_RANGE(uargs->rel, blkno); |
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uargs->buffer = ReadBuffer(uargs->rel, blkno); |
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if (!IS_INDEX(uargs->rel) || !IS_BTREE(uargs->rel)) |
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elog(ERROR, "bt_page_items() can be used only on b-tree index."); |
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uargs->page = BufferGetPage(uargs->buffer); |
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opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page); |
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if (P_ISDELETED(opaque)) |
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elog(NOTICE, "bt_page_items(): this page is deleted."); |
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fctx->max_calls = PageGetMaxOffsetNumber(uargs->page); |
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fctx->user_fctx = uargs; |
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MemoryContextSwitchTo(mctx); |
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} |
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fctx = SRF_PERCALL_SETUP(); |
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uargs = fctx->user_fctx; |
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if (fctx->call_cntr < fctx->max_calls) |
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{ |
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IndexTuple itup; |
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id = PageGetItemId(uargs->page, uargs->offset); |
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if (!ItemIdIsValid(id)) |
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elog(ERROR, "Invalid ItemId."); |
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itup = (IndexTuple) PageGetItem(uargs->page, id); |
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{ |
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int j = 0; |
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BlockNumber blkno = BlockIdGetBlockNumber(&(itup->t_tid.ip_blkid)); |
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values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", uargs->offset); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "(%u,%u)", blkno, itup->t_tid.ip_posid); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", IndexTupleSize(itup)); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%c", IndexTupleHasNulls(itup) ? 't' : 'f'); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%c", IndexTupleHasVarwidths(itup) ? 't' : 'f'); |
||||
|
||||
{ |
||||
int off; |
||||
char *dump; |
||||
char *ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info); |
||||
|
||||
dump = palloc(IndexTupleSize(itup) * 3); |
||||
memset(dump, 0, IndexTupleSize(itup) * 3); |
||||
|
||||
for (off = 0; |
||||
off < IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info); |
||||
off++) |
||||
{ |
||||
if (dump[0] == '\0') |
||||
sprintf(dump, "%02x", *(ptr + off) & 0xff); |
||||
else |
||||
{ |
||||
char buf[4]; |
||||
|
||||
sprintf(buf, " %02x", *(ptr + off) & 0xff); |
||||
strcat(dump, buf); |
||||
} |
||||
} |
||||
values[j] = dump; |
||||
} |
||||
|
||||
tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(uargs->tupd), values); |
||||
result = TupleGetDatum(TupleDescGetSlot(uargs->tupd), tuple); |
||||
} |
||||
|
||||
uargs->offset = uargs->offset + 1; |
||||
|
||||
SRF_RETURN_NEXT(fctx, result); |
||||
} |
||||
else |
||||
{ |
||||
ReleaseBuffer(uargs->buffer); |
||||
relation_close(uargs->rel, AccessShareLock); |
||||
|
||||
SRF_RETURN_DONE(fctx); |
||||
} |
||||
} |
||||
|
||||
|
||||
/* ------------------------------------------------
|
||||
* bt_metap() |
||||
* |
||||
* Get a btree meta-page information |
||||
* |
||||
* Usage: SELECT * FROM bt_metap('t1_pkey') |
||||
* ------------------------------------------------ |
||||
*/ |
||||
Datum |
||||
bt_metap(PG_FUNCTION_ARGS) |
||||
{ |
||||
text *relname = PG_GETARG_TEXT_P(0); |
||||
Buffer buffer; |
||||
|
||||
Relation rel; |
||||
RangeVar *relrv; |
||||
Datum result; |
||||
|
||||
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname)); |
||||
rel = relation_openrv(relrv, AccessShareLock); |
||||
|
||||
if (!IS_INDEX(rel) || !IS_BTREE(rel)) |
||||
elog(ERROR, "bt_metap() can be used only on b-tree index."); |
||||
|
||||
buffer = ReadBuffer(rel, 0); |
||||
|
||||
{ |
||||
BTMetaPageData *metad; |
||||
|
||||
TupleDesc tupleDesc; |
||||
int j; |
||||
char *values[BTMETAP_NCOLUMNS]; |
||||
HeapTuple tuple; |
||||
|
||||
Page page = BufferGetPage(buffer); |
||||
|
||||
metad = BTPageGetMeta(page); |
||||
|
||||
tupleDesc = RelationNameGetTupleDesc(BTMETAP_TYPE); |
||||
|
||||
j = 0; |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", metad->btm_magic); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", metad->btm_version); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", metad->btm_root); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", metad->btm_level); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", metad->btm_fastroot); |
||||
values[j] = palloc(32); |
||||
snprintf(values[j++], 32, "%d", metad->btm_fastlevel); |
||||
|
||||
tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc), |
||||
values); |
||||
|
||||
result = TupleGetDatum(TupleDescGetSlot(tupleDesc), tuple); |
||||
} |
||||
|
||||
ReleaseBuffer(buffer); |
||||
|
||||
relation_close(rel, AccessShareLock); |
||||
|
||||
PG_RETURN_DATUM(result); |
||||
} |
||||
|
||||
/* --------------------------------------------------------
|
||||
* pg_relpages() |
||||
* |
||||
* Get a number of pages of the table/index. |
||||
* |
||||
* Usage: SELECT pg_relpages('t1'); |
||||
* SELECT pg_relpages('t1_pkey'); |
||||
* -------------------------------------------------------- |
||||
*/ |
||||
Datum |
||||
pg_relpages(PG_FUNCTION_ARGS) |
||||
{ |
||||
text *relname = PG_GETARG_TEXT_P(0); |
||||
|
||||
Relation rel; |
||||
RangeVar *relrv; |
||||
int4 relpages; |
||||
|
||||
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname)); |
||||
rel = relation_openrv(relrv, AccessShareLock); |
||||
|
||||
relpages = RelationGetNumberOfBlocks(rel); |
||||
|
||||
relation_close(rel, AccessShareLock); |
||||
|
||||
PG_RETURN_INT32(relpages); |
||||
} |
||||
Loading…
Reference in new issue