Re: GSoC 2017: Foreign Key Arrays

On Mon, May 22, 2017 at 7:51 PM, Mark Rofail <markm(dot)rofail(at)gmail(dot)com> wrote:
> Cloned the git repo found @ https://github.com/postgres/postgres and
> identified the main two files I will be concerned with. (I know I may need
> to edit other files but these seem to where I will spend most of my summer)
>
> src/backend/commands/tablecmds.c
> src/backend/utils/ri_triggers.c
>
> I am yet to identify the files concerned with the GIN opclass. <-- if anyone
> can help with this

There's not only one GIN opclass. You can get a list like this:

select oid, * from pg_opclass where opcmethod = 2742;

Actually, you probably want to look for GIN opfamilies:

rhaas=# select oid, * from pg_opfamily where opfmethod = 2742;
oid | opfmethod | opfname | opfnamespace | opfowner
------+-----------+----------------+--------------+----------
2745 | 2742 | array_ops | 11 | 10
3659 | 2742 | tsvector_ops | 11 | 10
4036 | 2742 | jsonb_ops | 11 | 10
4037 | 2742 | jsonb_path_ops | 11 | 10
(4 rows)

To see which SQL functions are used to implement a particular
opfamily, use the OID from the previous step in a query like this:

rhaas=# select prosrc from pg_amop, pg_operator, pg_proc where
amopfamily = 2745 and amopopr = pg_operator.oid and oprcode =
pg_proc.oid;
prosrc
----------------
array_eq
arrayoverlap
arraycontains
arraycontained
(4 rows)

Then, you can look for those in the source tree. You can also search
for the associated support functions, e.g.:

rhaas=# select distinct amprocnum, prosrc from pg_amproc, pg_proc
where amprocfamily = 2745 and amproc = pg_proc.oid order by 1, 2;
amprocnum | prosrc
-----------+-----------------------
1 | bitcmp
1 | bpcharcmp
1 | btabstimecmp
1 | btboolcmp
1 | btcharcmp
1 | btfloat4cmp
1 | btfloat8cmp
1 | btint2cmp
1 | btint4cmp
1 | btint8cmp
1 | btnamecmp
1 | btoidcmp
1 | btoidvectorcmp
1 | btreltimecmp
1 | bttextcmp
1 | bttintervalcmp
1 | byteacmp
1 | cash_cmp
1 | date_cmp
1 | interval_cmp
1 | macaddr_cmp
1 | network_cmp
1 | numeric_cmp
1 | time_cmp
1 | timestamp_cmp
1 | timetz_cmp
2 | ginarrayextract
3 | ginqueryarrayextract
4 | ginarrayconsistent
6 | ginarraytriconsistent
(30 rows)

You might want to read https://www.postgresql.org/docs/devel/static/xindex.html

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company