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How can I be seeing shared locks? Is it because of foreign keys? Yes. SQL Server reverts to the locking implementation of the read committed isolation level when accessing a table for the purpose of validating foreign key constraints. This is required for correctness, and cannot be disabled. The behaviour applies only to data-modification statements. ...


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...why with clustered index, the deadlock is still there (though hit rate seems to be dropped) The question isn't precisely clear (e.g. how many updates and to which id values are in each transaction) but one obvious deadlock scenario arises with multiple single-row updates within a single transaction, where there is an overlap of [id] values, and the ...


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In general when running queries (SQL Statements) against a database you want all of the statements to successfully completed and if they do not revert data to what is was before you ran the sql statement. The overall concept you are looking for is ACID In order to provide this functionality, Databases generally support the concept of a transaction. When ...


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I'm not 100% sure I understand your question but anyway. Generally there's no need to wrap SELECT statements in transactions because they are read only, although you can specify the isolation level you want the SELECT to use (READ UNCOMITTED for instance). See here for a question about locks caused by SELECT statements in MySQL and how to change the type of ...


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BUFFER POOL INSTANCES The rule of thumb I usually use is based on a special program in in the Linux environment numactl --hardware When I run this, I get the following output sh-4.1# numactl --hardware available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 node 0 size: 49151 MB node 0 free: 241 MB node 1 cpus: 4 5 6 7 node 1 size: 32768 MB node 1 free: 39 MB ...


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You should use combination of innodb_buffer_pool_size in accourdance with innodb_buffer_pool_instances You should set the innodb_buffer_pool_instances configuration option to a value greater than 1 (the default) up to 64 (the maximum). This option takes effect only when you set the innodb_buffer_pool_size to a size of 1 gigabyte or more. The total size you ...



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