Details

    • Changed Behavior:
      The mechanism to replicate small tables was improved and thus the query profile changes in certain cases. See issue description for details.

      Description

      In prior versions the replication of small tables was triggered to improve the join performance (Global join computations are expensive. By replicating small tables to all nodes a global join could be locally executed).
      Even for small tables such a table replication could take seconds. For efficiency reasons replicated tables were stored persistently.
      As this mechanism was non-incremental the table replica was dropped and re-replicated whenever the underlying source table had been changed.

      Improvement
      This mechanism has been replaced by a much faster incremental mechanism that transfers as little data as possible.
      In particular, if the affected small table is often changed this improvement significantly reduces the runtime.

      Note

      If a query has to build a new index on a virtual replicated table, two indices are created: a global for later use and a local replicated index one for this query (not persistent). This might look unsual when profiling the query.

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              • Assignee:
                CaptainEXA Captain EXASOL
                Reporter:
                CaptainEXA Captain EXASOL
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                • Created:
                  Updated:
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