pgsql: Improve database detection logic in datachecksumsworker

Improve database detection logic in datachecksumsworker

The worker need to know whether a database which failed checksum
processing still exists, or has been dropped. This improves the
detection logic by checking for being partially dropped.

Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Reviewed-by: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com>
Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: /messages/by-id/9197F930-DDEB-4CAC-82A2-16FEC715CCE8@yesql.se

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1df361e3d82c5eddccdb10f10dbaf611f752e1b9

Modified Files
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src/backend/postmaster/datachecksum_state.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)