[COMMITTERS] pgsql: Refactor validation of new partitions a little bit.

Refactor validation of new partitions a little bit.

Move some logic that is currently in ATExecAttachPartition to
separate functions to facilitate future code reuse.

Ashutosh Bapat and Jeevan Ladhe

Discussion: http://postgr.es/m/CA+Tgmobbnamyvii0pRdg9pp_jLHSUvq7u5SiRrVV0tEFFU58Tg@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ecfe59e50fb8316ab7fc653419cd724c8b7a7dd7

Modified Files
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src/backend/commands/tablecmds.c | 318 +++++++++++++++++++++------------------
1 file changed, 172 insertions(+), 146 deletions(-)