Hi, Consider the following sequence of events:
s1 #> CREATE SCHEMA test_schema; s1 #> CREATE TABLE test_schema.c1(x int); Now open another session s2 and via gdb issue a breakpoint on heap_create_with_catalog() which is called by DefineRelation(). s2 #> CREATE TABLE test_schema.c2(y int); The above will break on the function. Now issue a drop schema in session s1 s1 #> DROP SCHEMA test_schema CASCADE; NOTICE: drop cascades to table test_schema.c1 DROP SCHEMA Continuing in gdb, also completes the creation of c2 table without any errors. We are now left with a dangling entry in pg_class along with all the corresponding data files in our data directory. The problem becomes worse if c2 was created using a TABLESPACE. Now dropping of that tablespace does not work at all. Am sure we can come up with myriad such other issues. Am sure other CREATE commands in this namespace will have similar issues when faced with a concurrent DROP SCHEMA. We definitely need some interlocking to handle this. For lack of better APIs, we could do a LockDatabaseObject() call in AccessShareLock mode on the namespace and release the same on completion of the creation of the object. Thoughts? Regards, Nikhils
