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  1. Ignite
  2. IGNITE-14846

Default statistics

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    • Ignite Flags:
      Docs Required, Release Notes Required

      Description

      To simplify optimizer and to get a little bit more accurate estimation Ignite can generate some default statistics for each table (each column and so on) based on tables metadata. For example:

      boolean non null field can produce a following statistics:

      min: false

      max: true

      nulls: 0

      distinct: 2

      total: <table_size>

      while

      uuid nullable column can produce:

      min: 00-00-00-00...

      max: FF-FF-FF-...

      nulls: <table_size> * 0.1

      distinct: <table_size> * 0.5

      total: <table size>

      It can be generated on the fly by statistics subsystem (and cached for future usages).

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              • Assignee:
                Unassigned
                Reporter:
                Berkov Alexander Belyak
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                Dates

                • Created:
                  Updated: