diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c index e5fefa3..cfa4a1d 100644 *** a/src/backend/commands/vacuum.c --- b/src/backend/commands/vacuum.c *************** vac_estimate_reltuples(Relation relation *** 648,670 **** * * We violate transaction semantics here by overwriting the rel's * existing pg_class tuple with the new values. This is reasonably ! * safe since the new values are correct whether or not this transaction ! * commits. The reason for this is that if we updated these tuples in ! * the usual way, vacuuming pg_class itself wouldn't work very well --- ! * by the time we got done with a vacuum cycle, most of the tuples in ! * pg_class would've been obsoleted. Of course, this only works for ! * fixed-size never-null columns, but these are. ! * ! * Note another assumption: that two VACUUMs/ANALYZEs on a table can't ! * run in parallel, nor can VACUUM/ANALYZE run in parallel with a ! * schema alteration such as adding an index, rule, or trigger. Otherwise ! * our updates of relhasindex etc might overwrite uncommitted updates. * * Another reason for doing it this way is that when we are in a lazy ! * VACUUM and have PROC_IN_VACUUM set, we mustn't do any updates --- ! * somebody vacuuming pg_class might think they could delete a tuple * marked with xmin = our xid. * * This routine is shared by VACUUM and ANALYZE. */ void --- 648,677 ---- * * We violate transaction semantics here by overwriting the rel's * existing pg_class tuple with the new values. This is reasonably ! * safe as long as we're sure that the new values are correct whether or ! * not this transaction commits. The reason for doing this is that if ! * we updated these tuples in the usual way, vacuuming pg_class itself ! * wouldn't work very well --- by the time we got done with a vacuum ! * cycle, most of the tuples in pg_class would've been obsoleted. Of ! * course, this only works for fixed-size not-null columns, but these are. * * Another reason for doing it this way is that when we are in a lazy ! * VACUUM and have PROC_IN_VACUUM set, we mustn't do any regular updates. ! * Somebody vacuuming pg_class might think they could delete a tuple * marked with xmin = our xid. * + * In addition to fundamentally nontransactional statistics such as + * relpages and relallvisible, we try to maintain certain lazily-updated + * DDL flags such as relhasindex, by clearing them if no longer correct. + * It's safe to do this in VACUUM, which can't run in parallel with + * CREATE INDEX/RULE/TRIGGER and can't be part of a transaction block. + * However, it's *not* safe to do it in an ANALYZE that's within a + * transaction block, because the current transaction might've dropped + * the last index; we'd think relhasindex should be cleared, but if the + * transaction later rolls back this would be wrong. So we refrain from + * updating the DDL flags if we're inside a transaction block. This is + * OK since postponing the flag maintenance is always allowable. + * * This routine is shared by VACUUM and ANALYZE. */ void *************** vac_update_relstats(Relation relation, *** 689,695 **** relid); pgcform = (Form_pg_class) GETSTRUCT(ctup); ! /* Apply required updates, if any, to copied tuple */ dirty = false; if (pgcform->relpages != (int32) num_pages) --- 696,702 ---- relid); pgcform = (Form_pg_class) GETSTRUCT(ctup); ! /* Apply statistical updates, if any, to copied tuple */ dirty = false; if (pgcform->relpages != (int32) num_pages) *************** vac_update_relstats(Relation relation, *** 707,738 **** pgcform->relallvisible = (int32) num_all_visible_pages; dirty = true; } - if (pgcform->relhasindex != hasindex) - { - pgcform->relhasindex = hasindex; - dirty = true; - } ! /* ! * If we have discovered that there are no indexes, then there's no ! * primary key either. This could be done more thoroughly... ! */ ! if (pgcform->relhaspkey && !hasindex) ! { ! pgcform->relhaspkey = false; ! dirty = true; ! } ! /* We also clear relhasrules and relhastriggers if needed */ ! if (pgcform->relhasrules && relation->rd_rules == NULL) ! { ! pgcform->relhasrules = false; ! dirty = true; ! } ! if (pgcform->relhastriggers && relation->trigdesc == NULL) { ! pgcform->relhastriggers = false; ! dirty = true; } /* --- 714,754 ---- pgcform->relallvisible = (int32) num_all_visible_pages; dirty = true; } ! /* Apply DDL updates, but not inside a transaction block (see above) */ ! if (!IsTransactionBlock()) { ! /* ! * If we didn't find any indexes, reset relhasindex. ! */ ! if (pgcform->relhasindex && !hasindex) ! { ! pgcform->relhasindex = false; ! dirty = true; ! } ! ! /* ! * If we have discovered that there are no indexes, then there's no ! * primary key either. This could be done more thoroughly... ! */ ! if (pgcform->relhaspkey && !hasindex) ! { ! pgcform->relhaspkey = false; ! dirty = true; ! } ! ! /* We also clear relhasrules and relhastriggers if needed */ ! if (pgcform->relhasrules && relation->rd_rules == NULL) ! { ! pgcform->relhasrules = false; ! dirty = true; ! } ! if (pgcform->relhastriggers && relation->trigdesc == NULL) ! { ! pgcform->relhastriggers = false; ! dirty = true; ! } } /* diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out index 10f45f2..f5ae511 100644 *** a/src/test/regress/expected/alter_table.out --- b/src/test/regress/expected/alter_table.out *************** ALTER TABLE logged1 SET UNLOGGED; -- sil *** 2517,2519 **** --- 2517,2539 ---- DROP TABLE logged3; DROP TABLE logged2; DROP TABLE logged1; + -- check presence of foreign key with transactional ANALYZE + CREATE TABLE check_fk_presence_1 (id int PRIMARY KEY, t text); + CREATE TABLE check_fk_presence_2 (id int REFERENCES check_fk_presence_1, t text); + BEGIN; + ALTER TABLE check_fk_presence_2 DROP CONSTRAINT check_fk_presence_2_id_fkey; + COPY check_fk_presence_2 FROM stdin; + ANALYZE check_fk_presence_2; + ALTER TABLE check_fk_presence_2 ADD FOREIGN KEY (table1_fk) REFERENCES check_fk_presence_1 (id); + ERROR: column "table1_fk" referenced in foreign key constraint does not exist + ROLLBACK; + \d check_fk_presence_2 + Table "public.check_fk_presence_2" + Column | Type | Modifiers + --------+---------+----------- + id | integer | + t | text | + Foreign-key constraints: + "check_fk_presence_2_id_fkey" FOREIGN KEY (id) REFERENCES check_fk_presence_1(id) + + DROP TABLE check_fk_presence_1, check_fk_presence_2; diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql index 12fd7c2..05d8226 100644 *** a/src/test/regress/sql/alter_table.sql --- b/src/test/regress/sql/alter_table.sql *************** ALTER TABLE logged1 SET UNLOGGED; -- sil *** 1676,1678 **** --- 1676,1691 ---- DROP TABLE logged3; DROP TABLE logged2; DROP TABLE logged1; + -- check presence of foreign key with transactional ANALYZE + CREATE TABLE check_fk_presence_1 (id int PRIMARY KEY, t text); + CREATE TABLE check_fk_presence_2 (id int REFERENCES check_fk_presence_1, t text); + BEGIN; + ALTER TABLE check_fk_presence_2 DROP CONSTRAINT check_fk_presence_2_id_fkey; + COPY check_fk_presence_2 FROM stdin; + 1 test + \. + ANALYZE check_fk_presence_2; + ALTER TABLE check_fk_presence_2 ADD FOREIGN KEY (table1_fk) REFERENCES check_fk_presence_1 (id); + ROLLBACK; + \d check_fk_presence_2 + DROP TABLE check_fk_presence_1, check_fk_presence_2;