DatabaseGrowthIncrement

V. Khorsun

(V.2.1) For better control of disk space preallocation, the new parameter DatabaseGrowthIncrement has been added to firebird.conf. It represents the upper limit for the size, in bytes, of the chunk of disk that will be requested for preallocation as pages for writes from the cache. Default: 134,217,728 bytes (128 MB).

For background information, please refer to the topic Enlarge Disk Allocation Chunks in the chapter “Global Improvements in Firebird 2.1”.

When the engine needs to initialize more disk space, it allocates a block that is 1/16th of the space already allocated, but not less than 128 KB and not greater than the DatabaseGrowthIncrement value. The DatabaseGrowthIncrement value can be raised to increase the maximum size of newly-allocated blocks to more than the default 128 MB. Set it to zero to disable preallocation.

Note

The lower limit of the block size is purposely hard-coded at 128 KB and cannot be reconfigured.
Space is not preallocated for database shadow files.
Preallocation is disabled for a database that has the “No reserve” option set.