Re: [HACKERS] GSoC 2017: Foreign Key Arrays

On Mon, May 22, 2017 at 7:51 PM, Mark Rofail <markm.rofail@gmail.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 |
103659|      2742 | tsvector_ops   |           11 |       104036 |      2742 | jsonb_ops      |           11 |
104037|      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_eqarrayoverlaparraycontainsarraycontained
(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