Oncheck taking too long ...

Posted in 1996

Nilesh N Kunvarji — Tue, 23 Jul 1996 21:06:54 -0400 — source: Informix-list mailing list archive (1991-1998)

We have OnLine 7.13 UC1 running on Solaris 2.4.. Our DB is approx 35+ GB in total. Some tables or over 2GB in size and quite a few are over 1GB. Approx 85-90 % of the tables in DB are very small. Our problem is that when we run oncheck -cI, the whole process takes approx. 4 hours. I have 13 concurrent oncheck -cI running. We have 32 processors on this machine of which 13 are allocated to OnLine (NOT affinity). I can drop and recreate all the indexes in about 1 Hour, by setting PSORT_NPROC environment. My question is, why does checking the indexes taking longer than creating the indexes ? Also during the oncheck process, one of the thread is going into a critical section, which in turn keeps the checkpoint waiting until its out of critical section (some checkpoint takes over 1500 seconds) Why does oncheck -cI go in to critical section ? Please advise. Nilesh K.