pgsql: VACUUM VERBOSE: Show dead items for an empty table.

VACUUM VERBOSE: Show dead items for an empty table.

Be consistent about the lines that VACUUM VERBOSE outputs by including
an "index scan not needed: " line for completely empty tables. This
makes the output more readable, especially with multiple distinct VACUUM
operations processed by the same VACUUM command. It's also more
consistent; even empty tables can use the failsafe, which wasn't
reported in the standard way until now.

Follow-up to commit 6e20f460, which taught VACUUM VERBOSE to be more
consistent about reporting on scanned pages with empty tables.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/bdb71dbe80d0560f84255e05b73f449e11007325

Modified Files
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src/backend/access/heap/vacuumlazy.c | 38 +++++++++++++++++-------------------
1 file changed, 18 insertions(+), 20 deletions(-)