CTE tables now materialise via MEMRDD (no file on disk), yet the
RunSelect cleanup loop was still stat-ing __cte_<name>.dbf for every
CTE in every CTE query. Profile after the FetchRow rewrite pinned
HbFileExists at 20.28% of total CPU — pure waste when MEMRDD is the
common path.
Add s_lCteDiskSeen flag, set only when the legacy DBFNTX fallback in
RunSelect actually opens a pre-existing __cte_<name>.dbf (line 1247
path — rare, only for sub-executors referencing a CTE by name on a
crashed-prior-run .dbf). Cleanup runs only when the flag is set.
pprof delta (full bench with cache enabled):
rawsyscalln: 25.56% → 8.50% (~17 points removed)
HbFileExists: 20.28% → 0% (dropped out of top)
Wall-clock unchanged (ENOENT stats are kernel-cached on Darwin), but
this removes the last visible avoidable syscall. What's left in the
profile (kevent, madvise, pthread_cond_*) is Go runtime + scheduler
overhead that application code can't touch.
FiveSql2 43/43, Harbour compat 56/56.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
CharlesKWON
c4ae88e76e