Remove some unnecessary code from multixact truncation With 64-bit multixact offsets, PerformMembersTruncation() doesn't need the starting offset anymore. The 'oldestOffset' value that TruncateMultiXact() calculates is no longer used for anything. Remove it, and the code to calculate it.
'oldestOffset' was included in the WAL record as 'startTruncMemb', which sounds nice if you e.g. look at the WAL with pg_waldump, but it was also confusing because we didn't actually use the value for determining what to truncate. Replaying the WAL would remove all segments older than 'endTruncMemb', regardless of 'startTruncMemb'. The 'startTruncOff' stored in the WAL record was similarly unnecessary even before 64-bit multixid offsets, it was stored just for the sake of symmetry with 'startTruncMemb'. Remove both from the WAL record, and rename the remaining 'endTruncOff' to 'oldestMulti' and 'endTruncMemb' to 'oldestOffset', for consistency with the variable names used for them in other places. Reviewed-by: Andrey Borodin <[email protected]> Discussion: https://www.postgresql.org/message-id/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/c4b71e6f60c005b54bd025ee30aaee3f22496622 Modified Files -------------- src/backend/access/rmgrdesc/mxactdesc.c | 5 +- src/backend/access/transam/multixact.c | 145 ++++++-------------------------- src/include/access/multixact.h | 10 +-- src/include/access/xlog_internal.h | 2 +- 4 files changed, 34 insertions(+), 128 deletions(-)
