Thread: BUG #17781: Assert in setrefs.c
The following bug has been logged on the website: Bug reference: 17781 Logged by: Robins Tharakan Email address: tharakan@gmail.com PostgreSQL version: 15.1 Operating system: Ubuntu 20.04 Description: This assert() is easily reproducible as of aa69541046@master, although I can trace the issue back to last week's commit 2489d76c49. TRAP: failed Assert("nrm_match == NRM_SUBSET ? bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels, phv->phnullingrels) : bms_equal(subphv->phnullingrels, phv->phnullingrels)"), File: "setrefs.c", Line: 2845, PID: 3217440 Backtrace / SQL / backtrace full (excerpt) below. SQL === rollback; begin; create table t6(); create table n(a numeric); create table t(a text); create table l(); create table n2(n numeric); create table f(); SELECT subq_3.c1 AS c8 FROM t6 AS sample_0 LEFT JOIN (n AS ref_1 RIGHT JOIN f AS sample_1 ON NULL LEFT JOIN (n2 AS sample_3 RIGHT JOIN t AS sample_4 ON NULL) ON ref_1.a = sample_3.n LEFT JOIN ((SELECT NULL AS c1 FROM l AS ref_2) AS subq_3 INNER JOIN pg_catalog.pg_stat_gssapi AS ref_4 ON NULL) ON ref_4.principal !~~ sample_4.a) ON NULL; Checking (aa69541046~49) - b448f1c8d8 - Crash Checking (aa69541046~50) - 2489d76c49 - Crash Checking (aa69541046~51) - ec7e053a98 - Success Checking (aa69541046~52) - fe9e658f4d - Success Backtrace ========= Core was generated by `postgres: aa69541046@master@sqith: ubuntu postgres 127.0.'. Program terminated with signal SIGABRT, Aborted. #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007f5d5b59f859 in __GI_abort () at abort.c:79 #2 0x000055dbe02e80d7 in ExceptionalCondition ( conditionName=0x55dbe049fec0 "nrm_match == NRM_SUBSET ? bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels, phv->phnullingrels) : bms_equal(subphv->phnullingr"..., fileName=0x55dbe049f8ef "setrefs.c", lineNumber=2845) at assert.c:66 #3 0x000055dbdffd7e28 in search_indexed_tlist_for_phv (phv=0x55dbe14dc5c8, itlist=0x55dbe14e8a60, newvarno=-1, nrm_match=NRM_SUPERSET) at setrefs.c:2845 #4 0x000055dbdffd82df in fix_join_expr_mutator (node=0x55dbe14dc5c8, context=0x7ffdf5c7c660) at setrefs.c:3066 #5 0x000055dbdff14963 in expression_tree_mutator_impl (node=0x55dbe14e8840, mutator=0x55dbdffd80b7 <fix_join_expr_mutator>, context=0x7ffdf5c7c660) at nodeFuncs.c:3051 #6 0x000055dbdffd843b in fix_join_expr_mutator (node=0x55dbe14e8840, context=0x7ffdf5c7c660) at setrefs.c:3104 #7 0x000055dbdff14d6e in expression_tree_mutator_impl (node=0x55dbe14e8890, mutator=0x55dbdffd80b7 <fix_join_expr_mutator>, context=0x7ffdf5c7c660) at nodeFuncs.c:3137 #8 0x000055dbdffd843b in fix_join_expr_mutator (node=0x55dbe14e8890, context=0x7ffdf5c7c660) at setrefs.c:3104 #9 0x000055dbdffd80a1 in fix_join_expr (root=0x55dbe14d4f80, clauses=0x55dbe14e8890, outer_itlist=0x55dbe14e8a10, inner_itlist=0x55dbe14e8a60, acceptable_rel=0, rtoffset=0, nrm_match=NRM_SUPERSET, num_exec=2910) at setrefs.c:2999 #10 0x000055dbdffd7111 in set_join_references (root=0x55dbe14d4f80, join=0x55dbe14e87b0, rtoffset=0) at setrefs.c:2350 #11 0x000055dbdffd3ef9 in set_plan_refs (root=0x55dbe14d4f80, plan=0x55dbe14e87b0, rtoffset=0) at setrefs.c:870 #12 0x000055dbdffd2a1f in set_plan_references (root=0x55dbe14d4f80, plan=0x55dbe14e87b0) at setrefs.c:354 #13 0x000055dbdffc43cd in standard_planner (parse=0x55dbe14bd2c8, query_string=0x55dbe13951a8 "SELECT subq_3.c1 AS c8\nFROM t6 AS sample_0\n LEFT JOIN (n AS ref_1\n", ' ' <repeats 16 times>, "RIGHT JOIN f AS sample_1 ON NULL\n", ' ' <repeats 16 times>, "LEFT JOIN (n2 AS sample_3\n", ' ' <repeats 27 times>, "RIGHT JOIN t"..., cursorOptions=2048, boundParams=0x0) at planner.c:504 Backtrace full excerpt ====================== #2 0x000055dbe02e80d7 in ExceptionalCondition ( conditionName=0x55dbe049fec0 "nrm_match == NRM_SUBSET ? bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels, phv->phnullingrels) : bms_equal(subphv->phnullingr"..., fileName=0x55dbe049f8ef "setrefs.c", lineNumber=2845) at assert.c:66 No locals. #3 0x000055dbdffd7e28 in search_indexed_tlist_for_phv (phv=0x55dbe14dc5c8, itlist=0x55dbe14e8a60, newvarno=-1, nrm_match=NRM_SUPERSET) at setrefs.c:2845 subphv = 0x55dbe14e7120 newvar = 0x0 tle = 0x55dbe14e85f0 lc__state = {l = 0x55dbe14e8640, i = 0} lc = 0x55dbe14e8658 #4 0x000055dbdffd82df in fix_join_expr_mutator (node=0x55dbe14dc5c8, context=0x7ffdf5c7c660) at setrefs.c:3066 phv = 0x55dbe14dc5c8 newvar = 0x0 __func__ = "fix_join_expr_mutator" #5 0x000055dbdff14963 in expression_tree_mutator_impl (node=0x55dbe14e8840, mutator=0x55dbdffd80b7 <fix_join_expr_mutator>, context=0x7ffdf5c7c660) at nodeFuncs.c:3051 targetentry = 0x55dbe14e8840 newnode = 0x55dbe14e9820 __func__ = "expression_tree_mutator_impl" #6 0x000055dbdffd843b in fix_join_expr_mutator (node=0x55dbe14e8840, context=0x7ffdf5c7c660) at setrefs.c:3104 newvar = 0x15c31daf4ca7e00 __func__ = "fix_join_expr_mutator" #7 0x000055dbdff14d6e in expression_tree_mutator_impl (node=0x55dbe14e8890, mutator=0x55dbdffd80b7 <fix_join_expr_mutator>, context=0x7ffdf5c7c660) at nodeFuncs.c:3137 temp__state = {l = 0x55dbe14e8890, i = 0} resultlist = 0x0 temp = 0x55dbe14e88a8 __func__ = "expression_tree_mutator_impl" #8 0x000055dbdffd843b in fix_join_expr_mutator (node=0x55dbe14e8890, context=0x7ffdf5c7c660) at setrefs.c:3104 newvar = 0x55dbe14e8a60 __func__ = "fix_join_expr_mutator" #9 0x000055dbdffd80a1 in fix_join_expr (root=0x55dbe14d4f80, clauses=0x55dbe14e8890, outer_itlist=0x55dbe14e8a10, inner_itlist=0x55dbe14e8a60, acceptable_rel=0, rtoffset=0, nrm_match=NRM_SUPERSET, num_exec=2910) at setrefs.c:2999 context = {root = 0x55dbe14d4f80, outer_itlist = 0x55dbe14e8a10, inner_itlist = 0x55dbe14e8a60, acceptable_rel = 0, rtoffset = 0, nrm_match = NRM_SUPERSET, num_exec = 2910} #10 0x000055dbdffd7111 in set_join_references (root=0x55dbe14d4f80, join=0x55dbe14e87b0, rtoffset=0) at setrefs.c:2350 outer_plan = 0x55dbe14e8560 inner_plan = 0x55dbe14e86f0 outer_itlist = 0x55dbe14e8a10 inner_itlist = 0x55dbe14e8a60 __func__ = "set_join_references" #11 0x000055dbdffd3ef9 in set_plan_refs (root=0x55dbe14d4f80, plan=0x55dbe14e87b0, rtoffset=0) at setrefs.c:870 l = 0x55dbe1395090 __func__ = "set_plan_refs" #12 0x000055dbdffd2a1f in set_plan_references (root=0x55dbe14d4f80, plan=0x55dbe14e87b0) at setrefs.c:354 result = 0x55dbe14dc108 glob = 0x55dbe14d6678 rtoffset = 0 lc = 0x0 #13 0x000055dbdffc43cd in standard_planner (parse=0x55dbe14bd2c8, query_string=0x55dbe13951a8 "SELECT subq_3.c1 AS c8\nFROM t6 AS sample_0\n LEFT JOIN (n AS ref_1\n", ' ' <repeats 16 times>, "RIGHT JOIN f AS sample_1 ON NULL\n", ' ' <repeats 16 times>, "LEFT JOIN (n2 AS sample_3\n", ' ' <repeats 27 times>, "RIGHT JOIN t"..., cursorOptions=2048, boundParams=0x0) at planner.c:504 result = 0x0 glob = 0x55dbe14d6678 tuple_fraction = 0 root = 0x55dbe14d4f80 final_rel = 0x55dbe14e81f0 best_path = 0x55dbe14e8050 top_plan = 0x55dbe14e87b0 lp = 0x4d430000 lr = 0x55dbe14d55a0 Thanks to SQLSmith / SQLReduce for the find. - Robins Tharakan Amazon Web Services
PG Bug reporting form <noreply@postgresql.org> writes: > This assert() is easily reproducible as of aa69541046@master, although I can > trace the issue back to last week's commit 2489d76c49. Pushed a fix, thanks! regards, tom lane
Hi Tom, Assuming this persistence is helpful overall, now I see a different SQL can still trigger the same assert(). On Wed, 8 Feb 2023 at 09:56, Tom Lane <tgl@sss.pgh.pa.us> wrote: > PG Bug reporting form <noreply@postgresql.org> writes: > > This assert() is easily reproducible as of aa69541046@master, although I can > > trace the issue back to last week's commit 2489d76c49. > > Pushed a fix, thanks! TRAP: failed Assert("nrm_match == NRM_SUBSET ? bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels, phv->phnullingrels) : bms_equal(subphv->phnullingrels, phv->phnullingrels)"), File: "setrefs.c", Line: 2845, PID: 803757 SQL === rollback; begin; create table t(); SELECT ref_1.definition AS c4 FROM t AS sample_1 LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL WHERE pg_catalog."user"() IS NOT NULL; Checking (fee7b77b90~0) - fee7b77b90 - Crash Checking (fee7b77b90~1) - e2c78e7ab4 - Success Checking (fee7b77b90~2) - 2cbbffff05 - Success === Backtrace - PID 803757 - fee7b77b90@master === Core was generated by `postgres: fee7b77b90@master@sqith: ubuntu t 127.0.0.1(60194) SELECT '. Program terminated with signal SIGABRT, Aborted. #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007f76d487e859 in __GI_abort () at abort.c:79 #2 0x000055c7f48e9126 in ExceptionalCondition ( conditionName=0x55c7f4aa0ec0 "nrm_match == NRM_SUBSET ? bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels, phv->phnullingrels) : bms_equal(subphv->phnullingr"..., fileName=0x55c7f4aa08ef "setrefs.c", lineNumber=2845) at assert.c:66 #3 0x000055c7f45d8df7 in search_indexed_tlist_for_phv (phv=0x55c7f6bd3b68, itlist=0x55c7f6bdf988, newvarno=-2, nrm_match=NRM_EQUAL) at setrefs.c:2845 #4 0x000055c7f45d959c in fix_upper_expr_mutator (node=0x55c7f6bd3b68, context=0x7ffec773f9e0) at setrefs.c:3188 #5 0x000055c7f45d9482 in fix_upper_expr (root=0x55c7f6bcca28, node=0x55c7f6bd3b68, subplan_itlist=0x55c7f6bdf988, newvarno=-2, rtoffset=0, nrm_match=NRM_EQUAL, num_exec=2910) at setrefs.c:3158 #6 0x000055c7f45d8271 in set_upper_references (root=0x55c7f6bcca28, plan=0x55c7f6bdf6e8, rtoffset=0) at setrefs.c:2423 #7 0x000055c7f45d5406 in set_plan_refs (root=0x55c7f6bcca28, plan=0x55c7f6bdf6e8, rtoffset=0) at setrefs.c:1034 #8 0x000055c7f45d39ee in set_plan_references (root=0x55c7f6bcca28, plan=0x55c7f6bdf6e8) at setrefs.c:354 #9 0x000055c7f45c539c in standard_planner (parse=0x55c7f6a5f7f8, query_string=0x55c7f6a5e508 "SELECT ref_1.definition AS c4\nFROM t AS sample_1\n LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL\nWHERE pg_catalog.\"user\"() IS NOT NULL;", cursorOptions=2048, boundParams=0x0) at planner.c:504 #10 0x00007f76d186c08b in pgss_planner (parse=0x55c7f6a5f7f8, query_string=0x55c7f6a5e508 "SELECT ref_1.definition AS c4\nFROM t AS sample_1\n LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL\nWHERE pg_catalog.\"user\"() IS NOT NULL;", cursorOptions=2048, boundParams=0x0) at pg_stat_statements.c:954 #11 0x000055c7f45c4c3d in planner (parse=0x55c7f6a5f7f8, query_string=0x55c7f6a5e508 "SELECT ref_1.definition AS c4\nFROM t AS sample_1\n LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL\nWHERE pg_catalog.\"user\"() IS NOT NULL;", cursorOptions=2048, boundParams=0x0) at planner.c:279 #12 0x000055c7f4709d72 in pg_plan_query (querytree=0x55c7f6a5f7f8, query_string=0x55c7f6a5e508 "SELECT ref_1.definition AS c4\nFROM t AS sample_1\n LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL\nWHERE pg_catalog.\"user\"() IS NOT NULL;", cursorOptions=2048, boundParams=0x0) at postgres.c:870 #13 0x000055c7f4709eca in pg_plan_queries (querytrees=0x55c7f6bb4eb8, query_string=0x55c7f6a5e508 "SELECT ref_1.definition AS c4\nFROM t AS sample_1\n LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL\nWHERE pg_catalog.\"user\"() IS NOT NULL;", cursorOptions=2048, boundParams=0x0) at postgres.c:962 #14 0x000055c7f470a2ad in exec_simple_query ( query_string=0x55c7f6a5e508 "SELECT ref_1.definition AS c4\nFROM t AS sample_1\n LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL\nWHERE pg_catalog.\"user\"() IS NOT NULL;") at postgres.c:1156 #15 0x000055c7f470f163 in PostgresMain (dbname=0x55c7f6a59478 "t", username=0x55c7f6a9f5f8 "ubuntu") at postgres.c:4565 #16 0x000055c7f4637d4d in BackendRun (port=0x55c7f6a953d0) at postmaster.c:4461 #17 0x000055c7f4637620 in BackendStartup (port=0x55c7f6a953d0) at postmaster.c:4189 #18 0x000055c7f4633a4f in ServerLoop () at postmaster.c:1779 #19 0x000055c7f4633324 in PostmasterMain (argc=3, argv=0x55c7f6a573d0) at postmaster.c:1463 #20 0x000055c7f44e65eb in main (argc=3, argv=0x55c7f6a573d0) at main.c:200 === Backtrace FULL - PID 803757 - fee7b77b90@master === #2 0x000055c7f48e9126 in ExceptionalCondition ( conditionName=0x55c7f4aa0ec0 "nrm_match == NRM_SUBSET ? bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels, phv->phnullingrels) : bms_equal(subphv->phnullingr"..., fileName=0x55c7f4aa08ef "setrefs.c", lineNumber=2845) at assert.c:66 No locals. #3 0x000055c7f45d8df7 in search_indexed_tlist_for_phv (phv=0x55c7f6bd3b68, itlist=0x55c7f6bdf988, newvarno=-2, nrm_match=NRM_EQUAL) at setrefs.c:2845 subphv = 0x55c7f6bdeaa8 newvar = 0x16e455bdfc6eef00 tle = 0x55c7f6bdf1b8 lc__state = {l = 0x55c7f6bdf208, i = 0} lc = 0x55c7f6bdf220 #4 0x000055c7f45d959c in fix_upper_expr_mutator (node=0x55c7f6bd3b68, context=0x7ffec773f9e0) at setrefs.c:3188 phv = 0x55c7f6bd3b68 newvar = 0x55c7f6a5e3f0 __func__ = "fix_upper_expr_mutator" #5 0x000055c7f45d9482 in fix_upper_expr (root=0x55c7f6bcca28, node=0x55c7f6bd3b68, subplan_itlist=0x55c7f6bdf988, newvarno=-2, rtoffset=0, nrm_match=NRM_EQUAL, num_exec=2910) at setrefs.c:3158 context = {root = 0x55c7f6bcca28, subplan_itlist = 0x55c7f6bdf988, newvarno = -2, rtoffset = 0, nrm_match = NRM_EQUAL, num_exec = 2910} #6 0x000055c7f45d8271 in set_upper_references (root=0x55c7f6bcca28, plan=0x55c7f6bdf6e8, rtoffset=0) at setrefs.c:2423 tle = 0x55c7f6bdf778 newexpr = 0x8 l__state = {l = 0x55c7f6bdf7c8, i = 0} subplan = 0x55c7f6bdf508 subplan_itlist = 0x55c7f6bdf988 output_targetlist = 0x0 l = 0x55c7f6bdf7e0 #7 0x000055c7f45d5406 in set_plan_refs (root=0x55c7f6bcca28, plan=0x55c7f6bdf6e8, rtoffset=0) at setrefs.c:1034 splan = 0x55c7f6bdf6e8 l = 0x55c7f6a5e3f0 __func__ = "set_plan_refs" #8 0x000055c7f45d39ee in set_plan_references (root=0x55c7f6bcca28, plan=0x55c7f6bdf6e8) at setrefs.c:354 result = 0x55c7f6bd3b18 glob = 0x55c7f6bcbea8 rtoffset = 0 lc = 0x0 #9 0x000055c7f45c539c in standard_planner (parse=0x55c7f6a5f7f8, query_string=0x55c7f6a5e508 "SELECT ref_1.definition AS c4\nFROM t AS sample_1\n LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL\nWHERE pg_catalog.\"user\"() IS NOT NULL;", cursorOptions=2048, boundParams=0x0) at planner.c:504 result = 0x0 glob = 0x55c7f6bcbea8 tuple_fraction = 0 root = 0x55c7f6bcca28 final_rel = 0x55c7f6bdd948 best_path = 0x55c7f6bdef38 top_plan = 0x55c7f6bdf6e8 lp = 0x4d430000 lr = 0x55c7f6bb4eb8 2023-02-08 01:35:21.274 UTC [4051201] LOG: server process (PID 803757) was terminated by signal 6: Aborted 2023-02-08 01:35:21.274 UTC [4051201] DETAIL: Failed process was running: SELECT ref_1.definition AS c4 FROM t AS sample_1 LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL WHERE pg_catalog."user"() IS NOT NULL; 2023-02-08 01:35:21.274 UTC [4051201] LOG: terminating any other active server processes As earlier, thanks to SQLSmith / SQLReduce. - Robins Tharakan Amazon Web Services
On Wed, Feb 8, 2023 at 1:52 PM Robins Tharakan <tharakan@gmail.com> wrote:
Hi Tom,
Assuming this persistence is helpful overall, now I see a
different SQL can still trigger the same assert().
On Wed, 8 Feb 2023 at 09:56, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> PG Bug reporting form <noreply@postgresql.org> writes:
> > This assert() is easily reproducible as of aa69541046@master, although I can
> > trace the issue back to last week's commit 2489d76c49.
>
> Pushed a fix, thanks!
TRAP: failed Assert("nrm_match == NRM_SUBSET ?
bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match
== NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels,
phv->phnullingrels) : bms_equal(subphv->phnullingrels,
phv->phnullingrels)"), File: "setrefs.c", Line: 2845, PID: 803757
SQL
===
rollback;
begin;
create table t();
SELECT ref_1.definition AS c4
FROM t AS sample_1
LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL
WHERE pg_catalog."user"() IS NOT NULL;
I've looked at this a little bit and I think it's a different issue. It
seems when we've decided that a left join can be removed, we neglect to
remove references to the target rel from PlaceHolderVar->phrels in
remove_rel_from_query. And it turns out that PlaceHolderVar->phrels is
used later in build_joinrel_tlist to check whether the PHV actually
comes from the nullable side of an outer join. I verified that with the
following change and it seems can fix this query.
--- a/src/backend/optimizer/plan/analyzejoins.c
+++ b/src/backend/optimizer/plan/analyzejoins.c
@@ -429,11 +429,16 @@ remove_rel_from_query(PlannerInfo *root, int relid, int ojrelid,
}
else
{
+ PlaceHolderVar *phv = phinfo->ph_var;
+
phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, relid);
phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, ojrelid);
Assert(!bms_is_empty(phinfo->ph_eval_at));
phinfo->ph_needed = bms_del_member(phinfo->ph_needed, relid);
phinfo->ph_needed = bms_del_member(phinfo->ph_needed, ojrelid);
+
+ phv->phrels = bms_del_member(phv->phrels, relid);
+ phv->phrels = bms_del_member(phv->phrels, ojrelid);
}
Thanks
Richard
seems when we've decided that a left join can be removed, we neglect to
remove references to the target rel from PlaceHolderVar->phrels in
remove_rel_from_query. And it turns out that PlaceHolderVar->phrels is
used later in build_joinrel_tlist to check whether the PHV actually
comes from the nullable side of an outer join. I verified that with the
following change and it seems can fix this query.
--- a/src/backend/optimizer/plan/analyzejoins.c
+++ b/src/backend/optimizer/plan/analyzejoins.c
@@ -429,11 +429,16 @@ remove_rel_from_query(PlannerInfo *root, int relid, int ojrelid,
}
else
{
+ PlaceHolderVar *phv = phinfo->ph_var;
+
phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, relid);
phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, ojrelid);
Assert(!bms_is_empty(phinfo->ph_eval_at));
phinfo->ph_needed = bms_del_member(phinfo->ph_needed, relid);
phinfo->ph_needed = bms_del_member(phinfo->ph_needed, ojrelid);
+
+ phv->phrels = bms_del_member(phv->phrels, relid);
+ phv->phrels = bms_del_member(phv->phrels, ojrelid);
}
Thanks
Richard
On Wed, Feb 8, 2023 at 3:02 PM Richard Guo <guofenglinux@gmail.com> wrote:
On Wed, Feb 8, 2023 at 1:52 PM Robins Tharakan <tharakan@gmail.com> wrote:Hi Tom,
Assuming this persistence is helpful overall, now I see a
different SQL can still trigger the same assert().
On Wed, 8 Feb 2023 at 09:56, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> PG Bug reporting form <noreply@postgresql.org> writes:
> > This assert() is easily reproducible as of aa69541046@master, although I can
> > trace the issue back to last week's commit 2489d76c49.
>
> Pushed a fix, thanks!
TRAP: failed Assert("nrm_match == NRM_SUBSET ?
bms_is_subset(phv->phnullingrels, subphv->phnullingrels) : nrm_match
== NRM_SUPERSET ? bms_is_subset(subphv->phnullingrels,
phv->phnullingrels) : bms_equal(subphv->phnullingrels,
phv->phnullingrels)"), File: "setrefs.c", Line: 2845, PID: 803757
SQL
===
rollback;
begin;
create table t();
SELECT ref_1.definition AS c4
FROM t AS sample_1
LEFT JOIN pg_catalog.pg_rules AS ref_1 ON NULL
WHERE pg_catalog."user"() IS NOT NULL;I've looked at this a little bit and I think it's a different issue. It
seems when we've decided that a left join can be removed, we neglect to
remove references to the target rel from PlaceHolderVar->phrels in
remove_rel_from_query. And it turns out that PlaceHolderVar->phrels is
used later in build_joinrel_tlist to check whether the PHV actually
comes from the nullable side of an outer join. I verified that with the
following change and it seems can fix this query.
--- a/src/backend/optimizer/plan/analyzejoins.c
+++ b/src/backend/optimizer/plan/analyzejoins.c
@@ -429,11 +429,16 @@ remove_rel_from_query(PlannerInfo *root, int relid, int ojrelid,
}
else
{
+ PlaceHolderVar *phv = phinfo->ph_var;
+
phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, relid);
phinfo->ph_eval_at = bms_del_member(phinfo->ph_eval_at, ojrelid);
Assert(!bms_is_empty(phinfo->ph_eval_at));
phinfo->ph_needed = bms_del_member(phinfo->ph_needed, relid);
phinfo->ph_needed = bms_del_member(phinfo->ph_needed, ojrelid);
+
+ phv->phrels = bms_del_member(phv->phrels, relid);
+ phv->phrels = bms_del_member(phv->phrels, ojrelid);
}
Hmm. I begin to wonder if it's better to use phinfo->ph_eval_at instead
in build_joinrel_tlist when we check whether the PHV actually comes from
the nullable side of an outer join.
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -1095,9 +1095,9 @@ build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
phv = copyObject(phv);
/* See comments above to understand this logic */
if (sjinfo->ojrelid != 0 &&
- (bms_is_subset(phv->phrels, sjinfo->syn_righthand) ||
+ (bms_is_subset(phinfo->ph_eval_at, sjinfo->syn_righthand) ||
(sjinfo->jointype == JOIN_FULL &&
- bms_is_subset(phv->phrels, sjinfo->syn_lefthand))))
+ bms_is_subset(phinfo->ph_eval_at, sjinfo->syn_lefthand))))
Even so it seems we still need to update phv->phrels in
remove_rel_from_query when we remove a left join. Otherwise it'd be
weird to observe that phrels contains some already-removed relids.
Thanks
Richard
in build_joinrel_tlist when we check whether the PHV actually comes from
the nullable side of an outer join.
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -1095,9 +1095,9 @@ build_joinrel_tlist(PlannerInfo *root, RelOptInfo *joinrel,
phv = copyObject(phv);
/* See comments above to understand this logic */
if (sjinfo->ojrelid != 0 &&
- (bms_is_subset(phv->phrels, sjinfo->syn_righthand) ||
+ (bms_is_subset(phinfo->ph_eval_at, sjinfo->syn_righthand) ||
(sjinfo->jointype == JOIN_FULL &&
- bms_is_subset(phv->phrels, sjinfo->syn_lefthand))))
+ bms_is_subset(phinfo->ph_eval_at, sjinfo->syn_lefthand))))
Even so it seems we still need to update phv->phrels in
remove_rel_from_query when we remove a left join. Otherwise it'd be
weird to observe that phrels contains some already-removed relids.
Thanks
Richard
Richard Guo <guofenglinux@gmail.com> writes: > Hmm. I begin to wonder if it's better to use phinfo->ph_eval_at instead > in build_joinrel_tlist when we check whether the PHV actually comes from > the nullable side of an outer join. I wondered about that too, but I think phrels is probably preferable, because it is fundamentally a syntactic attribute and what we are after here is matching the syntactic structure. I could be convinced that that's wrong, but I'd want to see an actual counterexample. > Even so it seems we still need to update phv->phrels in > remove_rel_from_query when we remove a left join. Otherwise it'd be > weird to observe that phrels contains some already-removed relids. Agreed, that's a good catch. As the comment for remove_rel_from_query says, * We are not terribly thorough here. It's not surprising that the requirements for it advance over time. (At one point I wrote some code that taught it to clean out the removed relids from EquivalenceClasses, which doesn't need to happen right now because we don't ever put outer-join quals into EquivalenceClasses. I don't think I included that in any of the published versions of the patch series, but it's going to need to reappear eventually.) regards, tom lane
Robins Tharakan <tharakan@gmail.com> writes: > Assuming this persistence is helpful overall, now I see a > different SQL can still trigger the same assert(). It's very helpful, thank you! I pushed Richard's fix for this. regards, tom lane
This assert() is still reproducible (as of 40d0b2d415@master) although intermittent when trying to reach manually, in that I could reduce to a simpler crash but after a while the crashes stop (maybe it's just lack of coffee). Owing to this, this time I only provide table-data instead of a simplified repro. What I can confirm is that the test setup easily steps on this every few minutes, so I'd say this still needs attention. TRAP: failed Assert("varattno <= 0 || (nrm_match == NRM_SUBSET ? bms_is_subset(var->varnullingrels, vinfo->varnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(vinfo->varnullingrels, var->varnullingrels) : bms_equal(vinfo->varnullingrels, var->varnullingrels))"), File: "setrefs.c", Line: 2792, PID: 2005079 2023-02-10 00:28:34.886 UTC [1798150] LOG: server process (PID 2005079) was terminated by signal 6: Aborted 2023-02-10 00:28:34.886 UTC [1798150] DETAIL: Failed process was running: SELECT FROM (SELECT NULL AS c1 LIMIT ALL) AS subq_2 RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2 LEFT JOIN (SELECT LIMIT ALL) AS subq_3 ON ref_3.name !~ subq_2.c1 RIGHT JOIN testxmlschema.test3 AS sample_2 ON ref_3.boolean = sample_2.c1 postgres=# select int2 is null, int8 is null, boolean is null, count(*) from caster group by 1,2,3; ?column? | ?column? | ?column? | count ----------+----------+----------+------- t | t | t | 80 (1 row) postgres=# \d testxmlschema.test3 Table "testxmlschema.test3" Column | Type | Collation | Nullable | Default --------+-------------------+-----------+----------+--------- c1 | boolean | | | c2 | testboolxmldomain | | | c3 | date | | | c4 | testdatexmldomain | | | postgres=# table testxmlschema.test3 ; c1 | c2 | c3 | c4 ----+----+------------+------------ t | t | 2013-02-21 | 2013-02-21 (1 row) === Backtrace - PID 2005079 - 40d0b2d415@master === Core was generated by `postgres: 40d0b2d415@master@sqith: ubuntu postgres 127.0.0.1(39074) SELECT '. Program terminated with signal SIGABRT, Aborted. #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007fbd65b54859 in __GI_abort () at abort.c:79 #2 0x000055da10f04d9d in ExceptionalCondition ( conditionName=0x55da110bcde8 "varattno <= 0 || (nrm_match == NRM_SUBSET ? bms_is_subset(var->varnullingrels, vinfo->varnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(vinfo->varnullingrels, var->varnullingrels) : bms_equa"..., fileName=0x55da110bc90f "setrefs.c", lineNumber=2792) at assert.c:66 #3 0x000055da10bf3d35 in search_indexed_tlist_for_var (var=0x55da123a4178, itlist=0x55da123adeb0, newvarno=-2, rtoffset=0, nrm_match=NRM_EQUAL) at setrefs.c:2792 #4 0x000055da10bf419e in fix_join_expr_mutator (node=0x55da123a4178, context=0x7ffe3bd446a0) at setrefs.c:3016 #5 0x000055da10b30d6e in expression_tree_mutator_impl (node=0x55da123a3e78, mutator=0x55da10bf4129 <fix_join_expr_mutator>, context=0x7ffe3bd446a0) at nodeFuncs.c:3137 #6 0x000055da10bf44ad in fix_join_expr_mutator (node=0x55da123a3e78, context=0x7ffe3bd446a0) at setrefs.c:3104 #7 0x000055da10b2fbd9 in expression_tree_mutator_impl (node=0x55da123a40b8, mutator=0x55da10bf4129 <fix_join_expr_mutator>, context=0x7ffe3bd446a0) at nodeFuncs.c:2771 #8 0x000055da10bf44ad in fix_join_expr_mutator (node=0x55da123a40b8, context=0x7ffe3bd446a0) at setrefs.c:3104 #9 0x000055da10b30d6e in expression_tree_mutator_impl (node=0x55da123ad820, mutator=0x55da10bf4129 <fix_join_expr_mutator>, context=0x7ffe3bd446a0) at nodeFuncs.c:3137 #10 0x000055da10bf44ad in fix_join_expr_mutator (node=0x55da123ad820, context=0x7ffe3bd446a0) at setrefs.c:3104 #11 0x000055da10bf4113 in fix_join_expr (root=0x55da123949f0, clauses=0x55da123ad820, outer_itlist=0x55da123adeb0, inner_itlist=0x55da123ae080, acceptable_rel=0, rtoffset=0, nrm_match=NRM_EQUAL, num_exec=2) at setrefs.c:2999 #12 0x000055da10bf2ee3 in set_join_references (root=0x55da123949f0, join=0x55da123ad850, rtoffset=0) at setrefs.c:2260 #13 0x000055da10beff6b in set_plan_refs (root=0x55da123949f0, plan=0x55da123ad850, rtoffset=0) at setrefs.c:870 #14 0x000055da10beea91 in set_plan_references (root=0x55da123949f0, plan=0x55da123ad850) at setrefs.c:354 #15 0x000055da10be043f in standard_planner (parse=0x55da1229de28, query_string=0x55da1226a508 "SELECT\nFROM (SELECT NULL AS c1\n LIMIT ALL) AS subq_2\n RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2\n LEFT JOIN (SELECT\n", ' ' <repeats 16 times>, "LIMIT ALL) AS subq_3 ON ref_3.name !~"..., cursorOptions=2048, boundParams=0x0) at planner.c:504 #16 0x00007fbd62b4208b in pgss_planner (parse=0x55da1229de28, query_string=0x55da1226a508 "SELECT\nFROM (SELECT NULL AS c1\n LIMIT ALL) AS subq_2\n RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2\n LEFT JOIN (SELECT\n", ' ' <repeats 16 times>, "LIMIT ALL) AS subq_3 ON ref_3.name !~"..., cursorOptions=2048, boundParams=0x0) at pg_stat_statements.c:954 #17 0x000055da10bdfce0 in planner (parse=0x55da1229de28, query_string=0x55da1226a508 "SELECT\nFROM (SELECT NULL AS c1\n LIMIT ALL) AS subq_2\n RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2\n LEFT JOIN (SELECT\n", ' ' <repeats 16 times>, "LIMIT ALL) AS subq_3 ON ref_3.name !~"..., cursorOptions=2048, boundParams=0x0) at planner.c:279 #18 0x000055da10d24f88 in pg_plan_query (querytree=0x55da1229de28, query_string=0x55da1226a508 "SELECT\nFROM (SELECT NULL AS c1\n LIMIT ALL) AS subq_2\n RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2\n LEFT JOIN (SELECT\n", ' ' <repeats 16 times>, "LIMIT ALL) AS subq_3 ON ref_3.name !~"..., cursorOptions=2048, boundParams=0x0) at postgres.c:870 #19 0x000055da10d250e0 in pg_plan_queries (querytrees=0x55da123949c0, query_string=0x55da1226a508 "SELECT\nFROM (SELECT NULL AS c1\n LIMIT ALL) AS subq_2\n RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2\n LEFT JOIN (SELECT\n", ' ' <repeats 16 times>, "LIMIT ALL) AS subq_3 ON ref_3.name !~"..., cursorOptions=2048, boundParams=0x0) at postgres.c:962 #20 0x000055da10d254c3 in exec_simple_query ( query_string=0x55da1226a508 "SELECT\nFROM (SELECT NULL AS c1\n LIMIT ALL) AS subq_2\n RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2\n LEFT JOIN (SELECT\n", ' ' <repeats 16 times>, "LIMIT ALL) AS subq_3 ON ref_3.name !~"...) at postgres.c:1156 #21 0x000055da10d2a379 in PostgresMain (dbname=0x55da122aa2e8 "postgres", username=0x55da12265478 "ubuntu") at postgres.c:4565 #22 0x000055da10c52dd6 in BackendRun (port=0x55da122a72b0) at postmaster.c:4461 #23 0x000055da10c526a9 in BackendStartup (port=0x55da122a72b0) at postmaster.c:4189 #24 0x000055da10c4ead8 in ServerLoop () at postmaster.c:1779 #25 0x000055da10c4e3ad in PostmasterMain (argc=3, argv=0x55da122633d0) at postmaster.c:1463 #26 0x000055da10b015eb in main (argc=3, argv=0x55da122633d0) at main.c:200 === Backtrace FULL - PID 2005079 - 40d0b2d415@master === #2 0x000055da10f04d9d in ExceptionalCondition ( conditionName=0x55da110bcde8 "varattno <= 0 || (nrm_match == NRM_SUBSET ? bms_is_subset(var->varnullingrels, vinfo->varnullingrels) : nrm_match == NRM_SUPERSET ? bms_is_subset(vinfo->varnullingrels, var->varnullingrels) : bms_equa"..., fileName=0x55da110bc90f "setrefs.c", lineNumber=2792) at assert.c:66 No locals. #3 0x000055da10bf3d35 in search_indexed_tlist_for_var (var=0x55da123a4178, itlist=0x55da123adeb0, newvarno=-2, rtoffset=0, nrm_match=NRM_EQUAL) at setrefs.c:2792 newvar = 0x55da123ae140 varno = 1 varattno = 1 vinfo = 0x55da123aded0 i = 0 #4 0x000055da10bf419e in fix_join_expr_mutator (node=0x55da123a4178, context=0x7ffe3bd446a0) at setrefs.c:3016 var = 0x55da123a4178 newvar = 0x55da10b2690d <lappend+133> __func__ = "fix_join_expr_mutator" #5 0x000055da10b30d6e in expression_tree_mutator_impl (node=0x55da123a3e78, mutator=0x55da10bf4129 <fix_join_expr_mutator>, context=0x7ffe3bd446a0) at nodeFuncs.c:3137 temp__state = {l = 0x55da123a3e78, i = 1} resultlist = 0x55da123adc10 temp = 0x55da123a41d0 __func__ = "expression_tree_mutator_impl" #6 0x000055da10bf44ad in fix_join_expr_mutator (node=0x55da123a3e78, context=0x7ffe3bd446a0) at setrefs.c:3104 newvar = 0x0 __func__ = "fix_join_expr_mutator" #7 0x000055da10b2fbd9 in expression_tree_mutator_impl (node=0x55da123a40b8, mutator=0x55da10bf4129 <fix_join_expr_mutator>, context=0x7ffe3bd446a0) at nodeFuncs.c:2771 expr = 0x55da123a40b8 newnode = 0x55da123ae0a0 __func__ = "expression_tree_mutator_impl" #8 0x000055da10bf44ad in fix_join_expr_mutator (node=0x55da123a40b8, context=0x7ffe3bd446a0) at setrefs.c:3104 newvar = 0xe0e36faee4a53e00 __func__ = "fix_join_expr_mutator" #9 0x000055da10b30d6e in expression_tree_mutator_impl (node=0x55da123ad820, mutator=0x55da10bf4129 <fix_join_expr_mutator>, context=0x7ffe3bd446a0) at nodeFuncs.c:3137 temp__state = {l = 0x55da123ad820, i = 0} resultlist = 0x0 temp = 0x55da123ad838 __func__ = "expression_tree_mutator_impl" #10 0x000055da10bf44ad in fix_join_expr_mutator (node=0x55da123ad820, context=0x7ffe3bd446a0) at setrefs.c:3104 newvar = 0x55da123ae080 __func__ = "fix_join_expr_mutator" #11 0x000055da10bf4113 in fix_join_expr (root=0x55da123949f0, clauses=0x55da123ad820, outer_itlist=0x55da123adeb0, inner_itlist=0x55da123ae080, acceptable_rel=0, rtoffset=0, nrm_match=NRM_EQUAL, num_exec=2) at setrefs.c:2999 context = {root = 0x55da123949f0, outer_itlist = 0x55da123adeb0, inner_itlist = 0x55da123ae080, acceptable_rel = 0, rtoffset = 0, nrm_match = NRM_EQUAL, num_exec = 2} #12 0x000055da10bf2ee3 in set_join_references (root=0x55da123949f0, join=0x55da123ad850, rtoffset=0) at setrefs.c:2260 outer_plan = 0x55da123ad670 inner_plan = 0x55da123ad790 outer_itlist = 0x55da123adeb0 inner_itlist = 0x55da123ae080 __func__ = "set_join_references" #13 0x000055da10beff6b in set_plan_refs (root=0x55da123949f0, plan=0x55da123ad850, rtoffset=0) at setrefs.c:870 l = 0x55da1226a3f0 __func__ = "set_plan_refs" #14 0x000055da10beea91 in set_plan_references (root=0x55da123949f0, plan=0x55da123ad850) at setrefs.c:354 result = 0x55da10bcbe95 <create_plan_recurse+134> glob = 0x55da1226c2d8 rtoffset = 0 lc = 0x0 #15 0x000055da10be043f in standard_planner (parse=0x55da1229de28, query_string=0x55da1226a508 "SELECT\nFROM (SELECT NULL AS c1\n LIMIT ALL) AS subq_2\n RIGHT JOIN public.caster AS ref_3 ON ref_3.int8 > ref_3.int2\n LEFT JOIN (SELECT\n", ' ' <repeats 16 times>, "LIMIT ALL) AS subq_3 ON ref_3.name !~"..., cursorOptions=2048, boundParams=0x0) at planner.c:504 result = 0x55da10ee048d <SearchCatCacheInternal+607> glob = 0x55da1226c2d8 tuple_fraction = 0 root = 0x55da123949f0 final_rel = 0x55da123ab050 best_path = 0x55da123aaba0 top_plan = 0x55da123ad850 lp = 0x0 lr = 0x0 - Robins Tharakan Amazon Web Services
On Fri, 10 Feb 2023 at 17:20, Robins Tharakan <tharakan@gmail.com> wrote: > > What I can confirm is that the test setup easily steps on this every > few minutes, so I'd say this still needs attention. My bad. I should have said every hour or so. - robins