G
George Potemkin
Guest
I have found a rather strange behavior in Progress but I'm not sure whether it's a bug or not: the queries running by remote clients are reading the master block. The single-table queries read the master block once per query. For example: find first customer no-lock. or for each customer no-lock: end. Progress translates the joins into multiple single-table queries. So the query below will read the master block twice: for first customer no-lock, first order of customer no-lock: end. A server receives many messages from its remote clients but it reads the master block only when it receives a message with a single-table query. The same queries executed by self-service clients are NOT reading the master block. It's not a performance issue: the master block is not on LRU chain and "DB Buf S Lock" is used to read the block (no buffer lock waits). On the other hand this extra db request creates the contention on the BHT latch. And from a logical point of view the master block does not store any information needed to run a query. Is that an expected behavior? Tested with Progress V10.2B08/11.6 on Windows and 11.6 on Linux
Continue reading...
Continue reading...