mirror of
https://github.com/postgres/postgres.git
synced 2025-11-12 05:01:15 +03:00
a56a016ceb
now able to cope with assigning new relfilenode values to nailed-in-cache indexes, so they can be reindexed using the fully crash-safe method. This leaves only shared system indexes as special cases. Remove the 'index deactivation' code, since it provides no useful protection in the shared- index case. Require reindexing of shared indexes to be done in standalone mode, but remove other restrictions on REINDEX. -P (IgnoreSystemIndexes) now prevents using indexes for lookups, but does not disable index updates. It is therefore safe to allow from PGOPTIONS. Upshot: reindexing system catalogs can be done without a standalone backend for all cases except shared catalogs.
$Header: /cvsroot/pgsql/src/backend/storage/ipc/README,v 1.3 2003/07/24 22:04:09 tgl Exp $ Mon Jul 18 11:09:22 PDT 1988 W.KLAS Cache invalidation synchronization routines: =========================================== The cache synchronization is done using a message queue. Every backend can register a message which then has to be read by all backends. A message read by all backends is removed from the queue automatically. If a message has been lost because the buffer was full, all backends that haven't read this message will be told that they have to reset their cache state. This is done at the time when they try to read the message queue. The message queue is implemented as a shared buffer segment. Actually, the queue is a circle to allow fast inserting, reading (invalidate data) and maintaining the buffer.