Recommended config for fixed key/value lengths

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Hey @aruiz14

  • Should I tweak ValueThreshold , (e.g. using LSMOnlyOptions ) so all my data fits into the tree?

If your value size is less than 1 KB (the default value threshold), the values will be in LSM Tree. If you have sha256 as the value, it would take up 32 bytes and fit in the LSM Tree.

  • Given that the MemoryMap loading mode will pre-allocate 2*ValueLogFileSize = 2GB , most of this memory is unused, if I understand correctly. Is ValueLogFileSize=256MB a reasonable value?

That should be okay.

  • My data will only increase over time, what are the implications of using a too-small ValueLogFileSize ?

You’ll have many file descriptors open (1 for each file). I don’t think anything else would be affected.

You would have issues with disk usage since vlog files are not cleaned up quickly in the current release of badger. These disk issues will be fixed in next release of badger which will happen next month (the code is already in master).

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