Re: GSoC 2017: Foreign Key Arrays

• After finding the arraycontains function, I implemented
arraycontainselem that corresponds to the operator @<(anyarray,
anyelem)
◦ Please read the attached patch file to view my progress.

• In addition to src/backend/utils/adt/arrayfuncs.c where I
implemented arraycontainselem.

◦ I also edited pg_amop (src/include/catalog/pg_amop.h) since
it stores information about operators associated with access method
operator families.

+DATA(insert ( 2745 2277 2283 2 s 2753 2742 0 ));
{
2745: Oid amopfamily; (denotes gin array_ops)
277: Oid amoplefttype; (denotes anyaray)
2283: Oid amoprighttype; (denotes anyelem)
5: int16 amopstrategy; /* operator strategy number */ (denotes the new
startegy that is yet to be created)
's': char amoppurpose; (denotes 's' for search)
2753: Oid amopopr; (denotes the new operator Oid)
2742: Oid amopmethod;(denotes gin)
0: Oid amopsortfamily; (0 since search operator)
}

◦ And pg_operator (src/include/catalog/pg_operator.h) since it
stores information about operators.
+DATA(insert OID = 2753 ( "@>" PGNSP PGUID b f f 2277 2283 16 0 0
arraycontainselem 0 0 ));
{
"@>": NameData oprname; /* name of operator */
Oid oprnamespace; /* OID of namespace containing this oper */
Oid oprowner; /* operator owner */
'b': char oprkind; /* 'l', 'r', or 'b' */ (denotes infix)
'f': bool oprcanmerge; /* can be used in merge join? */
'f': bool oprcanhash; /* can be used in hash join? */
277: Oid oprleft; (denotes anyaray)
2283: Oid oprright; (denotes anyelem)
16: Oid oprresult; (denotes boolean)
0: Oid oprcom; /* OID of commutator oper, or 0 if none */ (needs to be
revisited)
0: Oid oprnegate; /* OID of negator oper, or 0 if none */ (needs to be
revisited)
arraycontainselem: regproc oprcode; /* OID of underlying function */
0: regproc oprrest; /* OID of restriction estimator, or 0 */
0: regproc oprjoin; /* OID of join estimator, or 0 */
}