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  1. Ignite
  2. IGNITE-5991

SQL: lazy ResultSet for map query

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Details

    • Improvement
    • Status: Resolved
    • Critical
    • Resolution: Fixed
    • 2.1
    • 2.3
    • sql

    Description

      Currently we move the whole ResultSet to memory when executing SQL query on mapper. If result set is large enough, this could easily bring server down due to high GC pressure or even OOME.

      To avoid that we should stream H2's ResultSet to our own consumer, which will construct a page and send it to the client When a page is sent, consumer will block current thread until "next page request" is received. This approach has disadvantage - query thread will be blocked. However, implementation should be fairly easy and will allow us to avoid OOMEs on server. In future we will improve it to minimize blocking (or even avoid it completely).

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          blocks

          Task - A task that needs to be done. IGNITE-6084 SQL: improve lazy execution threading model

          • Major - Major loss of function.
          • Closed
          is blocked by

          Improvement - An improvement or enhancement to an existing feature or task. IGNITE-6027 SQL: add "last" flag to GridQueryNextPageResponse

          • Major - Major loss of function.
          • Resolved
          is depended upon by

          Task - A task that needs to be done. IGNITE-6117 JDBC2: Propagate "lazy" flag

          • Major - Major loss of function.
          • Resolved

          Task - A task that needs to be done. IGNITE-6118 JDBC Thin: Propagate "lazy" flag

          • Major - Major loss of function.
          • Resolved

          Task - A task that needs to be done. IGNITE-6119 ODBC: Propagate "lazy" flag

          • Major - Major loss of function.
          • Resolved

          Task - A task that needs to be done. IGNITE-6121 .NET: Propagate SqlFieldsQuery.lazy property

          • Major - Major loss of function.
          • Resolved

          Task - A task that needs to be done. IGNITE-6122 CPP: Propagate SqlFieldsQuery.lazy property

          • Major - Major loss of function.
          • Resolved

          Task - A task that needs to be done. IGNITE-6120 Web Console: Propagate "lazy" flag on Query screen

          • Major - Major loss of function.
          • Closed
          is duplicated by

          Improvement - An improvement or enhancement to an existing feature or task. IGNITE-3481 Implement lazy query execution in H2.

          • Major - Major loss of function.
          • Closed
          relates to

          Task - A task that needs to be done. IGNITE-6208 SQL: Add documentation for lazy query execution

          • Major - Major loss of function.
          • Closed
          links to

          Web Link GitHub Pull Request #2437

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              vozerov Vladimir Ozerov
              vozerov Vladimir Ozerov
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              Dates

                Created:
                Updated:
                Resolved: