open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Declare lead() and lag() using anycompatible not anyelement.

Browse Source 
This allows use of a "default" expression that doesn't slavishly
match the data column's type.  Formerly you got something like
"function lag(numeric, integer, integer) does not exist", which
is not just unhelpful but actively misleading.

The SQL spec suggests that the default should be coerced to the data
column's type, but this implementation instead chooses the common
supertype, which seems at least as reasonable.

(Note: I took the opportunity to run "make reformat-dat-files" on
pg_proc.dat, so this commit includes some cosmetic changes to
recently-added entries that aren't related to lead/lag.)

Vik Fearing

Discussion: https://postgr.es/m/77675130-89da-dab1-51dd-492c93dcf5d1@postgresfriends.org
pull/57/head
Tom Lane 5 years ago
parent 40c24bfef9
commit 5c292e6b90
5 changed files with 58 additions and 24 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 16
      doc/src/sgml/func.sgml
  2. 2
      src/include/catalog/catversion.h
  3. 32
      src/include/catalog/pg_proc.dat
  4. 30
      src/test/regress/expected/window.out
  5. 2
      src/test/regress/sql/window.sql

16
doc/src/sgml/func.sgml
Unescape View File

@ -19594,17 +19594,17 @@ SELECT count(*) FROM sometable;
<indexterm>
<primary>lag</primary>
</indexterm>
<function>lag</function> ( <parameter>value</parameter> <type>anyelement</type>
<function>lag</function> ( <parameter>value</parameter> <type>anycompatible</type>
<optional>, <parameter>offset</parameter> <type>integer</type>
<optional>, <parameter>default</parameter> <type>anyelement</type> </optional></optional> )
<returnvalue>anyelement</returnvalue>
<optional>, <parameter>default</parameter> <type>anycompatible</type> </optional></optional> )
<returnvalue>anycompatible</returnvalue>
</para>
<para>
Returns <parameter>value</parameter> evaluated at
the row that is <parameter>offset</parameter>
rows before the current row within the partition; if there is no such
row, instead returns <parameter>default</parameter>
(which must be of the same type as
(which must be of a type compatible with
<parameter>value</parameter>).
Both <parameter>offset</parameter> and
<parameter>default</parameter> are evaluated
@ -19619,17 +19619,17 @@ SELECT count(*) FROM sometable;
<indexterm>
<primary>lead</primary>
</indexterm>
<function>lead</function> ( <parameter>value</parameter> <type>anyelement</type>
<function>lead</function> ( <parameter>value</parameter> <type>anycompatible</type>
<optional>, <parameter>offset</parameter> <type>integer</type>
<optional>, <parameter>default</parameter> <type>anyelement</type> </optional></optional> )
<returnvalue>anyelement</returnvalue>
<optional>, <parameter>default</parameter> <type>anycompatible</type> </optional></optional> )
<returnvalue>anycompatible</returnvalue>
</para>
<para>
Returns <parameter>value</parameter> evaluated at
the row that is <parameter>offset</parameter>
rows after the current row within the partition; if there is no such
row, instead returns <parameter>default</parameter>
(which must be of the same type as
(which must be of a type compatible with
<parameter>value</parameter>).
Both <parameter>offset</parameter> and
<parameter>default</parameter> are evaluated

2
src/include/catalog/catversion.h
Unescape View File

@ -53,6 +53,6 @@
*/
/* yyyymmddN */
#define CATALOG_VERSION_NO 202011042
#define CATALOG_VERSION_NO 202011043
#endif

32
src/include/catalog/pg_proc.dat
Unescape View File

@ -1563,11 +1563,11 @@
proname => 'string_to_array', proisstrict => 'f', prorettype => '_text',
proargtypes => 'text text text', prosrc => 'text_to_array_null' },
{ oid => '8432', descr => 'split delimited text',
proname => 'string_to_table', proisstrict => 'f', prorows => '1000',
proname => 'string_to_table', prorows => '1000', proisstrict => 'f',
proretset => 't', prorettype => 'text', proargtypes => 'text text',
prosrc => 'text_to_table' },
{ oid => '8433', descr => 'split delimited text, with null string',
proname => 'string_to_table', proisstrict => 'f', prorows => '1000',
proname => 'string_to_table', prorows => '1000', proisstrict => 'f',
proretset => 't', prorettype => 'text', proargtypes => 'text text text',
prosrc => 'text_to_table_null' },
{ oid => '395',
@ -5257,8 +5257,8 @@
proargnames => '{pid,status,receive_start_lsn,receive_start_tli,written_lsn,flushed_lsn,received_tli,last_msg_send_time,last_msg_receipt_time,latest_end_lsn,latest_end_time,slot_name,sender_host,sender_port,conninfo}',
prosrc => 'pg_stat_get_wal_receiver' },
{ oid => '8595', descr => 'statistics: information about replication slots',
proname => 'pg_stat_get_replication_slots', prorows => '10', proisstrict => 'f',
proretset => 't', provolatile => 's', proparallel => 'r',
proname => 'pg_stat_get_replication_slots', prorows => '10',
proisstrict => 'f', proretset => 't', provolatile => 's', proparallel => 'r',
prorettype => 'record', proargtypes => '',
proallargtypes => '{text,int8,int8,int8,int8,int8,int8,timestamptz}',
proargmodes => '{o,o,o,o,o,o,o,o}',
@ -5491,8 +5491,7 @@
{ oid => '1136', descr => 'statistics: information about WAL activity',
proname => 'pg_stat_get_wal', proisstrict => 'f', provolatile => 's',
proparallel => 'r', prorettype => 'record', proargtypes => '',
proallargtypes => '{int8,timestamptz}',
proargmodes => '{o,o}',
proallargtypes => '{int8,timestamptz}', proargmodes => '{o,o}',
proargnames => '{wal_buffers_full,stats_reset}',
prosrc => 'pg_stat_get_wal' },
@ -5615,8 +5614,9 @@
prorettype => 'void', proargtypes => 'text', prosrc => 'pg_stat_reset_slru' },
{ oid => '8596',
descr => 'statistics: reset collected statistics for a single replication slot',
proname => 'pg_stat_reset_replication_slot', proisstrict => 'f', provolatile => 'v',
prorettype => 'void', proargtypes => 'text', prosrc => 'pg_stat_reset_replication_slot' },
proname => 'pg_stat_reset_replication_slot', proisstrict => 'f',
provolatile => 'v', prorettype => 'void', proargtypes => 'text',
prosrc => 'pg_stat_reset_replication_slot' },
{ oid => '3163', descr => 'current trigger depth',
proname => 'pg_trigger_depth', provolatile => 's', proparallel => 'r',
@ -7833,9 +7833,11 @@
prosrc => 'pg_get_shmem_allocations' },
# memory context of local backend
{ oid => '2282', descr => 'information about all memory contexts of local backend',
proname => 'pg_get_backend_memory_contexts', prorows => '100', proretset => 't',
provolatile => 'v', proparallel => 'r', prorettype => 'record', proargtypes => '',
{ oid => '2282',
descr => 'information about all memory contexts of local backend',
proname => 'pg_get_backend_memory_contexts', prorows => '100',
proretset => 't', provolatile => 'v', proparallel => 'r',
prorettype => 'record', proargtypes => '',
proallargtypes => '{text,text,text,int4,int8,int8,int8,int8,int8}',
proargmodes => '{o,o,o,o,o,o,o,o,o}',
proargnames => '{name, ident, parent, level, total_bytes, total_nblocks, free_bytes, free_chunks, used_bytes}',
@ -9748,8 +9750,8 @@
proname => 'lag', prokind => 'w', prorettype => 'anyelement',
proargtypes => 'anyelement int4', prosrc => 'window_lag_with_offset' },
{ oid => '3108', descr => 'fetch the Nth preceding row value with default',
proname => 'lag', prokind => 'w', prorettype => 'anyelement',
proargtypes => 'anyelement int4 anyelement',
proname => 'lag', prokind => 'w', prorettype => 'anycompatible',
proargtypes => 'anycompatible int4 anycompatible',
prosrc => 'window_lag_with_offset_and_default' },
{ oid => '3109', descr => 'fetch the following row value',
proname => 'lead', prokind => 'w', prorettype => 'anyelement',
@ -9758,8 +9760,8 @@
proname => 'lead', prokind => 'w', prorettype => 'anyelement',
proargtypes => 'anyelement int4', prosrc => 'window_lead_with_offset' },
{ oid => '3111', descr => 'fetch the Nth following row value with default',
proname => 'lead', prokind => 'w', prorettype => 'anyelement',
proargtypes => 'anyelement int4 anyelement',
proname => 'lead', prokind => 'w', prorettype => 'anycompatible',
proargtypes => 'anycompatible int4 anycompatible',
prosrc => 'window_lead_with_offset_and_default' },
{ oid => '3112', descr => 'fetch the first row value',
proname => 'first_value', prokind => 'w', prorettype => 'anyelement',

30
src/test/regress/expected/window.out
Unescape View File

@ -300,6 +300,21 @@ SELECT lag(ten, four, 0) OVER (PARTITION BY four ORDER BY ten), ten, four FROM t
0 | 3 | 3
(10 rows)
SELECT lag(ten, four, 0.7) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10 ORDER BY four, ten;
lag | ten | four
-----+-----+------
0 | 0 | 0
0 | 0 | 0
4 | 4 | 0
0.7 | 1 | 1
1 | 1 | 1
1 | 7 | 1
7 | 9 | 1
0.7 | 0 | 2
0.7 | 1 | 3
0.7 | 3 | 3
(10 rows)
SELECT lead(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
lead | ten | four
------+-----+------
@ -345,6 +360,21 @@ SELECT lead(ten * 2, 1, -1) OVER (PARTITION BY four ORDER BY ten), ten, four FRO
-1 | 3 | 3
(10 rows)
SELECT lead(ten * 2, 1, -1.4) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10 ORDER BY four, ten;
lead | ten | four
------+-----+------
0 | 0 | 0
8 | 0 | 0
-1.4 | 4 | 0
2 | 1 | 1
14 | 1 | 1
18 | 7 | 1
-1.4 | 9 | 1
-1.4 | 0 | 2
6 | 1 | 3
-1.4 | 3 | 3
(10 rows)
SELECT first_value(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
first_value | ten | four
-------------+-----+------

2
src/test/regress/sql/window.sql
Unescape View File

@ -63,12 +63,14 @@ SELECT lag(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHER
SELECT lag(ten, four) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lag(ten, four, 0) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lag(ten, four, 0.7) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10 ORDER BY four, ten;
SELECT lead(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lead(ten * 2, 1) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lead(ten * 2, 1, -1) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;
SELECT lead(ten * 2, 1, -1.4) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10 ORDER BY four, ten;
SELECT first_value(ten) OVER (PARTITION BY four ORDER BY ten), ten, four FROM tenk1 WHERE unique2 < 10;

Write Preview
Loading…
Cancel
Save