bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
- int step_lastkeyno,
Bitmapset *step_nullkeys,
List *prefix);
static List *get_steps_using_prefix_recurse(GeneratePruningStepsContext *context,
bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
- int step_lastkeyno,
Bitmapset *step_nullkeys,
List *prefix,
ListCell *start,
pc->op_is_ne,
pc->expr,
pc->cmpfn,
- 0,
NULL,
NIL);
opsteps = list_concat(opsteps, pc_steps);
pc->op_is_ne,
pc->expr,
pc->cmpfn,
- pc->keyno,
NULL,
prefix);
opsteps = list_concat(opsteps, pc_steps);
false,
pc->expr,
pc->cmpfn,
- pc->keyno,
nullkeys,
prefix);
opsteps = list_concat(opsteps, pc_steps);
/*
* get_steps_using_prefix
- * Generate list of PartitionPruneStepOp steps each consisting of given
- * opstrategy
- *
- * To generate steps, step_lastexpr and step_lastcmpfn are appended to
- * expressions and cmpfns, respectively, extracted from the clauses in
- * 'prefix'. Actually, since 'prefix' may contain multiple clauses for the
- * same partition key column, we must generate steps for various combinations
- * of the clauses of different keys.
- *
- * For list/range partitioning, callers must ensure that step_nullkeys is
- * NULL, and that prefix contains at least one clause for each of the
- * partition keys earlier than one specified in step_lastkeyno if it's
- * greater than zero. For hash partitioning, step_nullkeys is allowed to be
- * non-NULL, but they must ensure that prefix contains at least one clause
- * for each of the partition keys other than those specified in step_nullkeys
- * and step_lastkeyno.
- *
- * For both cases, callers must also ensure that clauses in prefix are sorted
- * in ascending order of their partition key numbers.
+ * Generate a list of PartitionPruneStepOps based on the given input.
+ *
+ * 'step_lastexpr' and 'step_lastcmpfn' are the Expr and comparison function
+ * belonging to the final partition key that we have a clause for. 'prefix'
+ * is a list of PartClauseInfos for partition key numbers prior to the given
+ * 'step_lastexpr' and 'step_lastcmpfn'. 'prefix' may contain multiple
+ * PartClauseInfos belonging to a single partition key. We will generate a
+ * PartitionPruneStepOp for each combination of the given PartClauseInfos
+ * using, at most, one PartClauseInfo per partition key.
+ *
+ * For LIST and RANGE partitioned tables, callers must ensure that
+ * step_nullkeys is NULL, and that prefix contains at least one clause for
+ * each of the partition keys prior to the key that 'step_lastexpr' and
+ * 'step_lastcmpfn'belong to.
+ *
+ * For HASH partitioned tables, callers must ensure that 'prefix' contains at
+ * least one clause for each of the partition keys apart from the final key
+ * (the expr and comparison function for the final key are in 'step_lastexpr'
+ * and 'step_lastcmpfn'). A bit set in step_nullkeys can substitute clauses
+ * in the 'prefix' list for any given key. If a bit is set in 'step_nullkeys'
+ * for a given key, then there must be no PartClauseInfo for that key in the
+ * 'prefix' list.
+ *
+ * For each of the above cases, callers must ensure that PartClauseInfos in
+ * 'prefix' are sorted in ascending order of keyno.
*/
static List *
get_steps_using_prefix(GeneratePruningStepsContext *context,
bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
- int step_lastkeyno,
Bitmapset *step_nullkeys,
List *prefix)
{
+ /* step_nullkeys must be empty for RANGE and LIST partitioned tables */
Assert(step_nullkeys == NULL ||
context->rel->part_scheme->strategy == PARTITION_STRATEGY_HASH);
- /* Quick exit if there are no values to prefix with. */
+ /*
+ * No recursive processing is required when 'prefix' is an empty list. This
+ * occurs when there is only 1 partition key column.
+ */
if (list_length(prefix) == 0)
{
PartitionPruneStep *step;
return list_make1(step);
}
- /* Recurse to generate steps for various combinations. */
+ /* Recurse to generate steps for every combination of clauses. */
return get_steps_using_prefix_recurse(context,
step_opstrategy,
step_op_is_ne,
step_lastexpr,
step_lastcmpfn,
- step_lastkeyno,
step_nullkeys,
prefix,
list_head(prefix),
/*
* get_steps_using_prefix_recurse
- * Recursively generate combinations of clauses for different partition
- * keys and start generating steps upon reaching clauses for the greatest
- * column that is less than the one for which we're currently generating
- * steps (that is, step_lastkeyno)
+ * Generate and return a list of PartitionPruneStepOps using the 'prefix'
+ * list of PartClauseInfos starting at the 'start' cell.
+ *
+ * When 'prefix' contains multiple PartClauseInfos for a single partition key
+ * we create a PartitionPruneStepOp for each combination of duplicated
+ * PartClauseInfos. The returned list will contain a PartitionPruneStepOp
+ * for each unique combination of input PartClauseInfos containing at most one
+ * PartClauseInfo per partition key.
*
- * 'prefix' is the list of PartClauseInfos.
- * 'start' is where we should start iterating for the current invocation.
+ * 'prefix' is the input list of PartClauseInfos sorted by keyno.
+ * 'start' marks the cell that searching the 'prefix' list should start from.
* 'step_exprs' and 'step_cmpfns' each contains the expressions and cmpfns
* we've generated so far from the clauses for the previous part keys.
*/
bool step_op_is_ne,
Expr *step_lastexpr,
Oid step_lastcmpfn,
- int step_lastkeyno,
Bitmapset *step_nullkeys,
List *prefix,
ListCell *start,
List *result = NIL;
ListCell *lc;
int cur_keyno;
+ int final_keyno;
/* Actually, recursion would be limited by PARTITION_MAX_KEYS. */
check_stack_depth();
- /* Check if we need to recurse. */
Assert(start != NULL);
cur_keyno = ((PartClauseInfo *) lfirst(start))->keyno;
- if (cur_keyno < step_lastkeyno - 1)
+ final_keyno = ((PartClauseInfo *) llast(prefix))->keyno;
+
+ /* Check if we need to recurse. */
+ if (cur_keyno < final_keyno)
{
PartClauseInfo *pc;
ListCell *next_start;
/*
- * For each clause with cur_keyno, add its expr and cmpfn to
- * step_exprs and step_cmpfns, respectively, and recurse after setting
- * next_start to the ListCell of the first clause for the next
- * partition key.
+ * Find the first PartClauseInfo belonging to the next partition key, the
+ * next recursive call must start iteration of the prefix list from that
+ * point.
*/
for_each_cell(lc, prefix, start)
{
if (pc->keyno > cur_keyno)
break;
}
+
+ /* record where to start iterating in the next recursive call */
next_start = lc;
+ /*
+ * For each PartClauseInfo with keyno set to cur_keyno, add its expr and
+ * cmpfn to step_exprs and step_cmpfns, respectively, and recurse using
+ * 'next_start' as the starting point in the 'prefix' list.
+ */
for_each_cell(lc, prefix, start)
{
List *moresteps;
}
else
{
+ /* check the 'prefix' list is sorted correctly */
Assert(pc->keyno > cur_keyno);
break;
}
step_op_is_ne,
step_lastexpr,
step_lastcmpfn,
- step_lastkeyno,
step_nullkeys,
prefix,
next_start,
* each clause with cur_keyno, which is all clauses from here onward
* till the end of the list. Note that for hash partitioning,
* step_nullkeys is allowed to be non-empty, in which case step_exprs
- * would only contain expressions for the earlier partition keys that
- * are not specified in step_nullkeys.
+ * would only contain expressions for the partition keys that are not
+ * specified in step_nullkeys.
*/
Assert(list_length(step_exprs) == cur_keyno ||
!bms_is_empty(step_nullkeys));
Filter: ((a >= 1) AND (b >= 1) AND (d >= 0) AND (b = 2) AND (c = 2))
(2 rows)
-create table hp_prefix_test (a int, b int, c int, d int) partition by hash (a part_test_int4_ops, b part_test_int4_ops, c part_test_int4_ops, d part_test_int4_ops);
-create table hp_prefix_test_p1 partition of hp_prefix_test for values with (modulus 2, remainder 0);
-create table hp_prefix_test_p2 partition of hp_prefix_test for values with (modulus 2, remainder 1);
--- Test that get_steps_using_prefix() handles non-NULL step_nullkeys
-explain (costs off) select * from hp_prefix_test where a = 1 and b is null and c = 1 and d = 1;
- QUERY PLAN
--------------------------------------------------------------
- Seq Scan on hp_prefix_test_p1 hp_prefix_test
- Filter: ((b IS NULL) AND (a = 1) AND (c = 1) AND (d = 1))
-(2 rows)
-
drop table rp_prefix_test1;
drop table rp_prefix_test2;
drop table rp_prefix_test3;
+--
+-- Test that get_steps_using_prefix() handles IS NULL clauses correctly
+--
+create table hp_prefix_test (a int, b int, c int, d int)
+ partition by hash (a part_test_int4_ops, b part_test_int4_ops, c part_test_int4_ops, d part_test_int4_ops);
+-- create 8 partitions
+select 'create table hp_prefix_test_p' || x::text || ' partition of hp_prefix_test for values with (modulus 8, remainder ' || x::text || ');'
+from generate_Series(0,7) x;
+ ?column?
+------------------------------------------------------------------------------------------------------
+ create table hp_prefix_test_p0 partition of hp_prefix_test for values with (modulus 8, remainder 0);
+ create table hp_prefix_test_p1 partition of hp_prefix_test for values with (modulus 8, remainder 1);
+ create table hp_prefix_test_p2 partition of hp_prefix_test for values with (modulus 8, remainder 2);
+ create table hp_prefix_test_p3 partition of hp_prefix_test for values with (modulus 8, remainder 3);
+ create table hp_prefix_test_p4 partition of hp_prefix_test for values with (modulus 8, remainder 4);
+ create table hp_prefix_test_p5 partition of hp_prefix_test for values with (modulus 8, remainder 5);
+ create table hp_prefix_test_p6 partition of hp_prefix_test for values with (modulus 8, remainder 6);
+ create table hp_prefix_test_p7 partition of hp_prefix_test for values with (modulus 8, remainder 7);
+(8 rows)
+
+\gexec
+create table hp_prefix_test_p0 partition of hp_prefix_test for values with (modulus 8, remainder 0);
+create table hp_prefix_test_p1 partition of hp_prefix_test for values with (modulus 8, remainder 1);
+create table hp_prefix_test_p2 partition of hp_prefix_test for values with (modulus 8, remainder 2);
+create table hp_prefix_test_p3 partition of hp_prefix_test for values with (modulus 8, remainder 3);
+create table hp_prefix_test_p4 partition of hp_prefix_test for values with (modulus 8, remainder 4);
+create table hp_prefix_test_p5 partition of hp_prefix_test for values with (modulus 8, remainder 5);
+create table hp_prefix_test_p6 partition of hp_prefix_test for values with (modulus 8, remainder 6);
+create table hp_prefix_test_p7 partition of hp_prefix_test for values with (modulus 8, remainder 7);
+-- insert 16 rows, one row for each test to perform.
+insert into hp_prefix_test
+select
+ case a when 0 then null else 1 end,
+ case b when 0 then null else 2 end,
+ case c when 0 then null else 3 end,
+ case d when 0 then null else 4 end
+from
+ generate_series(0,1) a,
+ generate_series(0,1) b,
+ generate_Series(0,1) c,
+ generate_Series(0,1) d;
+-- Ensure partition pruning works correctly for each combination of IS NULL
+-- and equality quals. This may seem a little excessive, but there have been
+-- a number of bugs in this area over the years. We make use of row only
+-- output to reduce the size of the expected results.
+\t on
+select
+ 'explain (costs off) select tableoid::regclass,* from hp_prefix_test where ' ||
+ string_agg(c.colname || case when g.s & (1 << c.colpos) = 0 then ' is null' else ' = ' || (colpos+1)::text end, ' and ' order by c.colpos)
+from (values('a',0),('b',1),('c',2),('d',3)) c(colname, colpos), generate_Series(0,15) g(s)
+group by g.s
+order by g.s;
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d is null
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d = 4
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d = 4
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d = 4
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d = 4
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d = 4
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d = 4
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d = 4
+ explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d = 4
+
+\gexec
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d is null
+ Seq Scan on hp_prefix_test_p0 hp_prefix_test
+ Filter: ((a IS NULL) AND (b IS NULL) AND (c IS NULL) AND (d IS NULL))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d is null
+ Seq Scan on hp_prefix_test_p1 hp_prefix_test
+ Filter: ((b IS NULL) AND (c IS NULL) AND (d IS NULL) AND (a = 1))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d is null
+ Seq Scan on hp_prefix_test_p2 hp_prefix_test
+ Filter: ((a IS NULL) AND (c IS NULL) AND (d IS NULL) AND (b = 2))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d is null
+ Seq Scan on hp_prefix_test_p4 hp_prefix_test
+ Filter: ((c IS NULL) AND (d IS NULL) AND (a = 1) AND (b = 2))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d is null
+ Seq Scan on hp_prefix_test_p3 hp_prefix_test
+ Filter: ((a IS NULL) AND (b IS NULL) AND (d IS NULL) AND (c = 3))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d is null
+ Seq Scan on hp_prefix_test_p7 hp_prefix_test
+ Filter: ((b IS NULL) AND (d IS NULL) AND (a = 1) AND (c = 3))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d is null
+ Seq Scan on hp_prefix_test_p4 hp_prefix_test
+ Filter: ((a IS NULL) AND (d IS NULL) AND (b = 2) AND (c = 3))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d is null
+ Seq Scan on hp_prefix_test_p5 hp_prefix_test
+ Filter: ((d IS NULL) AND (a = 1) AND (b = 2) AND (c = 3))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d = 4
+ Seq Scan on hp_prefix_test_p4 hp_prefix_test
+ Filter: ((a IS NULL) AND (b IS NULL) AND (c IS NULL) AND (d = 4))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d = 4
+ Seq Scan on hp_prefix_test_p6 hp_prefix_test
+ Filter: ((b IS NULL) AND (c IS NULL) AND (a = 1) AND (d = 4))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d = 4
+ Seq Scan on hp_prefix_test_p5 hp_prefix_test
+ Filter: ((a IS NULL) AND (c IS NULL) AND (b = 2) AND (d = 4))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d = 4
+ Seq Scan on hp_prefix_test_p6 hp_prefix_test
+ Filter: ((c IS NULL) AND (a = 1) AND (b = 2) AND (d = 4))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d = 4
+ Seq Scan on hp_prefix_test_p4 hp_prefix_test
+ Filter: ((a IS NULL) AND (b IS NULL) AND (c = 3) AND (d = 4))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d = 4
+ Seq Scan on hp_prefix_test_p5 hp_prefix_test
+ Filter: ((b IS NULL) AND (a = 1) AND (c = 3) AND (d = 4))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d = 4
+ Seq Scan on hp_prefix_test_p6 hp_prefix_test
+ Filter: ((a IS NULL) AND (b = 2) AND (c = 3) AND (d = 4))
+
+explain (costs off) select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d = 4
+ Seq Scan on hp_prefix_test_p4 hp_prefix_test
+ Filter: ((a = 1) AND (b = 2) AND (c = 3) AND (d = 4))
+
+-- And ensure we get exactly 1 row from each. Again, all 16 possible combinations.
+select
+ 'select tableoid::regclass,* from hp_prefix_test where ' ||
+ string_agg(c.colname || case when g.s & (1 << c.colpos) = 0 then ' is null' else ' = ' || (colpos+1)::text end, ' and ' order by c.colpos)
+from (values('a',0),('b',1),('c',2),('d',3)) c(colname, colpos), generate_Series(0,15) g(s)
+group by g.s
+order by g.s;
+ select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d is null
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d is null
+ select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d is null
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d is null
+ select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d is null
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d is null
+ select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d is null
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d is null
+ select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d = 4
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d = 4
+ select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d = 4
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d = 4
+ select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d = 4
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d = 4
+ select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d = 4
+ select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d = 4
+
+\gexec
+select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d is null
+ hp_prefix_test_p0 | | | |
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d is null
+ hp_prefix_test_p1 | 1 | | |
+
+select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d is null
+ hp_prefix_test_p2 | | 2 | |
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d is null
+ hp_prefix_test_p4 | 1 | 2 | |
+
+select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d is null
+ hp_prefix_test_p3 | | | 3 |
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d is null
+ hp_prefix_test_p7 | 1 | | 3 |
+
+select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d is null
+ hp_prefix_test_p4 | | 2 | 3 |
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d is null
+ hp_prefix_test_p5 | 1 | 2 | 3 |
+
+select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c is null and d = 4
+ hp_prefix_test_p4 | | | | 4
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c is null and d = 4
+ hp_prefix_test_p6 | 1 | | | 4
+
+select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c is null and d = 4
+ hp_prefix_test_p5 | | 2 | | 4
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c is null and d = 4
+ hp_prefix_test_p6 | 1 | 2 | | 4
+
+select tableoid::regclass,* from hp_prefix_test where a is null and b is null and c = 3 and d = 4
+ hp_prefix_test_p4 | | | 3 | 4
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b is null and c = 3 and d = 4
+ hp_prefix_test_p5 | 1 | | 3 | 4
+
+select tableoid::regclass,* from hp_prefix_test where a is null and b = 2 and c = 3 and d = 4
+ hp_prefix_test_p6 | | 2 | 3 | 4
+
+select tableoid::regclass,* from hp_prefix_test where a = 1 and b = 2 and c = 3 and d = 4
+ hp_prefix_test_p4 | 1 | 2 | 3 | 4
+
+\t off
drop table hp_prefix_test;
--
-- Check that gen_partprune_steps() detects self-contradiction from clauses
-- that the caller arranges clauses in that prefix in the required order)
explain (costs off) select * from rp_prefix_test3 where a >= 1 and b >= 1 and b = 2 and c = 2 and d >= 0;
-create table hp_prefix_test (a int, b int, c int, d int) partition by hash (a part_test_int4_ops, b part_test_int4_ops, c part_test_int4_ops, d part_test_int4_ops);
-create table hp_prefix_test_p1 partition of hp_prefix_test for values with (modulus 2, remainder 0);
-create table hp_prefix_test_p2 partition of hp_prefix_test for values with (modulus 2, remainder 1);
-
--- Test that get_steps_using_prefix() handles non-NULL step_nullkeys
-explain (costs off) select * from hp_prefix_test where a = 1 and b is null and c = 1 and d = 1;
-
drop table rp_prefix_test1;
drop table rp_prefix_test2;
drop table rp_prefix_test3;
+
+--
+-- Test that get_steps_using_prefix() handles IS NULL clauses correctly
+--
+create table hp_prefix_test (a int, b int, c int, d int)
+ partition by hash (a part_test_int4_ops, b part_test_int4_ops, c part_test_int4_ops, d part_test_int4_ops);
+
+-- create 8 partitions
+select 'create table hp_prefix_test_p' || x::text || ' partition of hp_prefix_test for values with (modulus 8, remainder ' || x::text || ');'
+from generate_Series(0,7) x;
+\gexec
+
+-- insert 16 rows, one row for each test to perform.
+insert into hp_prefix_test
+select
+ case a when 0 then null else 1 end,
+ case b when 0 then null else 2 end,
+ case c when 0 then null else 3 end,
+ case d when 0 then null else 4 end
+from
+ generate_series(0,1) a,
+ generate_series(0,1) b,
+ generate_Series(0,1) c,
+ generate_Series(0,1) d;
+
+-- Ensure partition pruning works correctly for each combination of IS NULL
+-- and equality quals. This may seem a little excessive, but there have been
+-- a number of bugs in this area over the years. We make use of row only
+-- output to reduce the size of the expected results.
+\t on
+select
+ 'explain (costs off) select tableoid::regclass,* from hp_prefix_test where ' ||
+ string_agg(c.colname || case when g.s & (1 << c.colpos) = 0 then ' is null' else ' = ' || (colpos+1)::text end, ' and ' order by c.colpos)
+from (values('a',0),('b',1),('c',2),('d',3)) c(colname, colpos), generate_Series(0,15) g(s)
+group by g.s
+order by g.s;
+\gexec
+
+-- And ensure we get exactly 1 row from each. Again, all 16 possible combinations.
+select
+ 'select tableoid::regclass,* from hp_prefix_test where ' ||
+ string_agg(c.colname || case when g.s & (1 << c.colpos) = 0 then ' is null' else ' = ' || (colpos+1)::text end, ' and ' order by c.colpos)
+from (values('a',0),('b',1),('c',2),('d',3)) c(colname, colpos), generate_Series(0,15) g(s)
+group by g.s
+order by g.s;
+\gexec
+\t off
+
drop table hp_prefix_test;
--
projects / postgresql.git / commitdiff