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$PostgreSQL: pgsql/src/backend/storage/ipc/README,v 1.4 2003-11-29 19:51:56 pgsql Exp $
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Mon Jul 18 11:09:22 PDT 1988 W.KLAS
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Cache invalidation synchronization routines:
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===========================================
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The cache synchronization is done using a message queue. Every
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backend can register a message which then has to be read by
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all backends. A message read by all backends is removed from the
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queue automatically. If a message has been lost because the buffer
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was full, all backends that haven't read this message will be
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told that they have to reset their cache state. This is done
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at the time when they try to read the message queue.
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The message queue is implemented as a shared buffer segment. Actually,
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the queue is a circle to allow fast inserting, reading (invalidate data) and
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maintaining the buffer.