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Code and docs review for pg_column_size() patch.

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REL8_1_STABLE
Tom Lane 20 years ago
parent f023fc6689
commit 0001e98d54
4 changed files with 130 additions and 108 deletions
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  1. 109
      doc/src/sgml/func.sgml
  2. 76
      src/backend/access/heap/tuptoaster.c
  3. 49
      src/backend/utils/adt/varlena.c
  4. 4
      src/include/catalog/pg_proc.h

109
doc/src/sgml/func.sgml
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@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.275 2005/07/30 22:53:15 tgl Exp $
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.276 2005/08/02 16:11:56 tgl Exp $
PostgreSQL documentation
-->
@ -2206,14 +2206,6 @@ PostgreSQL documentation
<entry><literal>5</literal></entry>
</row>
<row>
<entry><literal><function>pg_column_size</function>(<parameter>string</parameter>)</literal></entry>
<entry><type>integer</type></entry>
<entry>Number of bytes required to store the value, which might be compressed</entry>
<entry><literal>pg_column_size('jo\\000se'::bytea)</literal></entry>
<entry><literal>5</literal></entry>
</row>
<row>
<entry><literal><function>position</function>(<parameter>substring</parameter> in <parameter>string</parameter>)</literal></entry>
<entry><type>integer</type></entry>
@ -9181,11 +9173,29 @@ SELECT set_config('log_statement_stats', 'off', false);
</para>
<para>
The functions shown in <xref
linkend="functions-admin-dbsize"> calculate the actual disk space
usage of database objects.
The functions shown in <xref linkend="functions-admin-dbsize"> calculate
the actual disk space usage of database objects.
</para>
<indexterm zone="functions-admin">
<primary>pg_column_size</primary>
</indexterm>
<indexterm zone="functions-admin">
<primary>pg_tablespace_size</primary>
</indexterm>
<indexterm zone="functions-admin">
<primary>pg_database_size</primary>
</indexterm>
<indexterm zone="functions-admin">
<primary>pg_relation_size</primary>
</indexterm>
<indexterm zone="functions-admin">
<primary>pg_complete_relation_size</primary>
</indexterm>
<indexterm zone="functions-admin">
<primary>pg_size_pretty</primary>
</indexterm>
<table id="functions-admin-dbsize">
<title>Database Object Size Functions</title>
<tgroup cols="3">
@ -9195,97 +9205,108 @@ SELECT set_config('log_statement_stats', 'off', false);
</thead>
<tbody>
<row>
<entry><function>pg_column_size</function>(<parameter>any</parameter>)</entry>
<entry><type>integer</type></entry>
<entry>Number of bytes used to store a particular value (possibly compressed)</entry>
</row>
<row>
<entry>
<literal><function>pg_tablespace_size</function>(<parameter>oid</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the total disk space used by the tablespace with the specified OID</entry>
<entry><type>bigint</type></entry>
<entry>Total disk space used by the tablespace with the specified OID</entry>
</row>
<row>
<entry>
<literal><function>pg_tablespace_size</function>(<parameter>name</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the total disk space used by the tablespace with the specified name</entry>
<entry><type>bigint</type></entry>
<entry>Total disk space used by the tablespace with the specified name</entry>
</row>
<row>
<entry>
<literal><function>pg_database_size</function>(<parameter>oid</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the total disk space used by the database with the specified OID</entry>
<entry><type>bigint</type></entry>
<entry>Total disk space used by the database with the specified OID</entry>
</row>
<row>
<entry>
<literal><function>pg_database_size</function>(<parameter>name</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the total disk space used by the database with the specified name</entry>
<entry><type>bigint</type></entry>
<entry>Total disk space used by the database with the specified name</entry>
</row>
<row>
<entry>
<literal><function>pg_relation_size</function>(<parameter>oid</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the disk space used by the table or index with the specified OID</entry>
<entry><type>bigint</type></entry>
<entry>Disk space used by the table or index with the specified OID</entry>
</row>
<row>
<entry>
<literal><function>pg_relation_size</function>(<parameter>text</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the disk space used by the index or table with the specified name.
The name may be prefixed with a schema name if required</entry>
<entry><type>bigint</type></entry>
<entry>Disk space used by the table or index with the specified name.
The name may be qualified with a schema name</entry>
</row>
<row>
<entry>
<literal><function>pg_complete_relation_size</function>(<parameter>oid</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the total disk space used by the table with the specified OID,
<entry><type>bigint</type></entry>
<entry>Total disk space used by the table with the specified OID,
including indexes and toasted data</entry>
</row>
<row>
<entry>
<literal><function>pg_complete_relation_size</function>(<parameter>text</parameter>)</literal>
</entry>
<entry><type>int8</type></entry>
<entry>Calculates the total disk space used by the table with the specified name,
including indexes and toasted data. The name may be prefixed with a schema name if
required</entry>
<entry><type>bigint</type></entry>
<entry>Total disk space used by the table with the specified name,
including indexes and toasted data.
The table name may be qualified with a schema name</entry>
</row>
<row>
<entry>
<literal><function>pg_size_pretty</function>(<parameter>int8</parameter>)</literal>
<literal><function>pg_size_pretty</function>(<parameter>bigint</parameter>)</literal>
</entry>
<entry><type>text</type></entry>
<entry>Formats the size value (in bytes) into a human readable format with size units </entry>
<entry>Converts a size in bytes into a human-readable format with size units</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
<function>pg_tablespace_size</> and <function>pg_database_size</> accept an
oid or name of a tablespace or database, and return the disk space usage of the specified object.
<function>pg_column_size</> shows the space used to store any individual
data value.
</para>
<indexterm zone="functions-admin">
<primary>pg_relation_size</primary>
</indexterm>
<para>
<function>pg_relation_size</> accepts the oid or name of a table, index or
<function>pg_tablespace_size</> and <function>pg_database_size</> accept
the OID or name of a tablespace or database, and return the total disk
space used therein.
</para>
<para>
<function>pg_relation_size</> accepts the OID or name of a table, index or
toast table, and returns the size in bytes.
</para>
<para>
<function>pg_complete_relation_size</> accepts the oid or name of a table or
toast table, and returns the size in bytes of the data and all associated
indexes and toast tables.
<function>pg_complete_relation_size</> accepts the OID or name of a table
or toast table, and returns the size in bytes of the data and all
associated indexes and toast tables.
</para>
<para>
<function>pg_size_pretty</> can be used to format the size of the
database objects in a human readable way, using kB, MB, GB or TB as appropriate.
<function>pg_size_pretty</> can be used to format the result of one of
the other functions in a human-readable way, using kB, MB, GB or TB as
appropriate.
</para>
</sect1>

76
src/backend/access/heap/tuptoaster.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.50 2005/07/06 19:02:52 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.51 2005/08/02 16:11:57 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -268,6 +268,38 @@ toast_raw_datum_size(Datum value)
return result;
}
/* ----------
* toast_datum_size
*
* Return the physical storage size (possibly compressed) of a varlena datum
* ----------
*/
Size
toast_datum_size(Datum value)
{
varattrib *attr = (varattrib *) DatumGetPointer(value);
Size result;
if (VARATT_IS_EXTERNAL(attr))
{
/*
* Attribute is stored externally - return the extsize whether
* compressed or not. We do not count the size of the toast
* pointer ... should we?
*/
result = attr->va_content.va_external.va_extsize;
}
else
{
/*
* Attribute is stored inline either compressed or not, just
* calculate the size of the datum in either case.
*/
result = VARSIZE(attr);
}
return result;
}
/* ----------
* toast_delete -
@ -1436,45 +1468,3 @@ toast_fetch_datum_slice(varattrib *attr, int32 sliceoffset, int32 length)
return result;
}
/* ----------
* toast_datum_size
*
* Show the (possibly compressed) size of a datum
* ----------
*/
Size
toast_datum_size(Datum value)
{
varattrib *attr = (varattrib *) DatumGetPointer(value);
Size result;
if (VARATT_IS_EXTERNAL(attr))
{
/*
* Attribute is stored externally - If it is compressed too,
* then we need to get the external datum and calculate its size,
* otherwise we just use the external rawsize.
*/
if (VARATT_IS_COMPRESSED(attr))
{
varattrib *attrext = toast_fetch_datum(attr);
result = VARSIZE(attrext);
pfree(attrext);
}
else
result = attr->va_content.va_external.va_rawsize;
}
else
{
/*
* Attribute is stored inline either compressed or not, just
* calculate the size of the datum in either case.
*/
result = VARSIZE(attr);
}
return result;
}

49
src/backend/utils/adt/varlena.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.130 2005/07/29 03:17:55 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.131 2005/08/02 16:11:57 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2574,38 +2574,49 @@ md5_bytea(PG_FUNCTION_ARGS)
}
/*
* Return the length of a datum, possibly compressed
* Return the size of a datum, possibly compressed
*
* Works on any data type
*/
Datum
pg_column_size(PG_FUNCTION_ARGS)
{
Datum value = PG_GETARG_DATUM(0);
int result;
Datum value = PG_GETARG_DATUM(0);
int32 result;
int typlen;
/* fn_extra stores the fixed column length, or -1 for varlena. */
if (fcinfo->flinfo->fn_extra == NULL) /* first call? */
/* On first call, get the input type's typlen, and save at *fn_extra */
if (fcinfo->flinfo->fn_extra == NULL)
{
/* On the first call lookup the datatype of the supplied argument */
Oid argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
int typlen = get_typlen(argtypeid);
/* Lookup the datatype of the supplied argument */
Oid argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
if (typlen == 0)
{
/* Oid not in pg_type, should never happen. */
typlen = get_typlen(argtypeid);
if (typlen == 0) /* should not happen */
elog(ERROR, "cache lookup failed for type %u", argtypeid);
}
fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
sizeof(int));
*(int *)fcinfo->flinfo->fn_extra = typlen;
*((int *) fcinfo->flinfo->fn_extra) = typlen;
}
else
typlen = *((int *) fcinfo->flinfo->fn_extra);
if (*(int *)fcinfo->flinfo->fn_extra != -1)
PG_RETURN_INT32(*(int *)fcinfo->flinfo->fn_extra);
if (typlen == -1)
{
/* varlena type, possibly toasted */
result = toast_datum_size(value);
}
else if (typlen == -2)
{
/* cstring */
result = strlen(DatumGetCString(value)) + 1;
}
else
{
result = toast_datum_size(value) - VARHDRSZ;
PG_RETURN_INT32(result);
/* ordinary fixed-width type */
result = typlen;
}
PG_RETURN_INT32(result);
}

4
src/include/catalog/pg_proc.h
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.379 2005/07/29 14:47:01 momjian Exp $
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.380 2005/08/02 16:11:57 tgl Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
@ -3701,7 +3701,7 @@ DATA(insert OID = 2560 ( pg_postmaster_start_time PGNSP PGUID 12 f f t f s 0 11
DESCR("postmaster start time");
/* Column storage size */
DATA(insert OID = 1269 ( pg_column_size PGNSP PGUID 12 f f t f i 1 23 "2276" _null_ _null_ _null_ pg_column_size - _null_ ));
DATA(insert OID = 1269 ( pg_column_size PGNSP PGUID 12 f f t f s 1 23 "2276" _null_ _null_ _null_ pg_column_size - _null_ ));
DESCR("bytes required to store the value, perhaps with compression");
/* new functions for Y-direction rtree opclasses */

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