*** 214,220 **** How do these other database servers manage high concurrency? ! They actually apply a relatively simple trick. All changes are done to memory (and appended to the journal) first, while the thread that commits changes to the filesystem will commit these changes only much later, while on his round across dirty memory records, he will pick up the changes and commits them to the filesystem. In this way, for example, you may get a counter-intuitive "Out of memory" error on SQL Server, when you delete all records from a large table. Why? Because, there is not enough space available to keep all these deleted records in memory, until the writing thread can commit these deletes to disk. --- 214,220 ---- How do these other database servers manage high concurrency? ! They actually apply a relatively simple trick. All changes are done to memory (and appended to the journal) first, while the thread that commits changes to the filesystem will commit these changes only much later, while on his round across dirty memory records, he will pick up the changes and commit them to the filesystem. In this way, for example, you may get a counter-intuitive "Out of memory" error on SQL Server, when you delete all records from a large table. Why? Because, there is not enough space available to keep all these deleted records in memory, until the writing thread can commit these deletes to disk.
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