The size of the .data file grows in operation although the total row count for CACHED tables has not gone up. Why?
HSQLDB tracks only up to a fixed number of the empty spaces left after DELETE or during UPDATE operations. If the delete rate is higher than insert rate, or large number of rows are updated in a single query, then some spaces are left empty. Both CHECKPOINT DEFRAG and SHUTDOWN COMPACT commands will remove the empty spaces. In version 2.0 empty spaces are tracked better and DEFRAG will be performed automatically, based on a user-defined property.
Related Questions
- I noticed CFS divides files into small blocks. Doesn this mean that as my file grows in size the probability that all of the blocks are present tends towards zero?
- The size of the .data file grows in operation although the total row count for CACHED tables has not gone up. Why?
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