[COMMITTERS] pgsql: Use weaker locks when updating pg_subscription_rel

Use weaker locks when updating pg_subscription_rel

The previously used ShareRowExclusiveLock, while technically probably
more correct, led to deadlocks during seemingly unrelated operations and
thus a poor experience.  Use RowExclusiveLock, like for most similar
catalog operations.  In some care cases, the user might see an error
from DDL commands.

Discussion: https://www.postgresql.org/message-id/flat/13592.1490851519%40sss.pgh.pa.us

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/521fd4795e3ec3d0b263b62e5eb58e1557be9c86

Modified Files
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src/backend/catalog/pg_subscription.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)