contrib/tsm_system_time

Author: simonat2ndQuadrant

contrib/tsm_system_time/.gitignore

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+# Generated subdirectories
+/log/
+/results/
+/tmp_check/

contrib/tsm_system_time/Makefile

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+# src/test/modules/tsm_system_time/Makefile
+
+MODULE_big = tsm_system_time
+OBJS = tsm_system_time.o $(WIN32RES)
+PGFILEDESC = "tsm_system_time - SYSTEM TABLESAMPLE method which accepts number rows of as a limit"
+
+EXTENSION = tsm_system_time
+DATA = tsm_system_time--1.0.sql
+
+REGRESS = tsm_system_time
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/tsm_system_time
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif

contrib/tsm_system_time/expected/tsm_system_time.out

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+CREATE EXTENSION tsm_system_time;
+CREATE TABLE test_tablesample (id int, name text) WITH (fillfactor=10); -- force smaller pages so we don't have to load too much data to get multiple pages
+INSERT INTO test_tablesample SELECT i, repeat(i::text, 1000) FROM generate_series(0, 30) s(i) ORDER BY i;
+ANALYZE test_tablesample;
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_time (1000);
+ count 
+-------
+    31
+(1 row)
+
+SELECT id FROM test_tablesample TABLESAMPLE system_time (1000) REPEATABLE (5432);
+ id 
+----
+  7
+ 14
+ 21
+ 28
+  4
+ 11
+ 18
+ 25
+  1
+  8
+ 15
+ 22
+ 29
+  5
+ 12
+ 19
+ 26
+  2
+  9
+ 16
+ 23
+ 30
+  6
+ 13
+ 20
+ 27
+  3
+ 10
+ 17
+ 24
+  0
+(31 rows)
+
+EXPLAIN SELECT id FROM test_tablesample TABLESAMPLE system_time (100) REPEATABLE (10);
+                                     QUERY PLAN                                     
+------------------------------------------------------------------------------------
+ Sample Scan (system_time) on test_tablesample  (cost=0.00..100.25 rows=25 width=4)
+(1 row)
+
+-- done
+DROP TABLE test_tablesample CASCADE;

contrib/tsm_system_time/sql/tsm_system_time.sql

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+CREATE EXTENSION tsm_system_time;
+
+CREATE TABLE test_tablesample (id int, name text) WITH (fillfactor=10); -- force smaller pages so we don't have to load too much data to get multiple pages
+
+INSERT INTO test_tablesample SELECT i, repeat(i::text, 1000) FROM generate_series(0, 30) s(i) ORDER BY i;
+ANALYZE test_tablesample;
+
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_time (1000);
+SELECT id FROM test_tablesample TABLESAMPLE system_time (1000) REPEATABLE (5432);
+
+EXPLAIN SELECT id FROM test_tablesample TABLESAMPLE system_time (100) REPEATABLE (10);
+
+-- done
+DROP TABLE test_tablesample CASCADE;

contrib/tsm_system_time/tsm_system_time--1.0.sql

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+/* src/test/modules/tablesample/tsm_system_time--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION tsm_system_time" to load this file. \quit
+
+CREATE FUNCTION tsm_system_time_init(internal, int4, int4)
+RETURNS void
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION tsm_system_time_nextblock(internal)
+RETURNS int4
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION tsm_system_time_nexttuple(internal, int4, int2)
+RETURNS int2
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION tsm_system_time_end(internal)
+RETURNS void
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION tsm_system_time_reset(internal)
+RETURNS void
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT;
+
+CREATE FUNCTION tsm_system_time_cost(internal, internal, internal, internal, internal, internal, internal)
+RETURNS void
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT;
+
+INSERT INTO pg_tablesample_method VALUES('system_time', false, true,
+	'tsm_system_time_init', 'tsm_system_time_nextblock',
+	'tsm_system_time_nexttuple', '-', 'tsm_system_time_end',
+	'tsm_system_time_reset', 'tsm_system_time_cost');
+