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Vladimir Steshin commented on IGNITE-16920: ------------------------------------------- Calcite doesn't use index, counting records in metapages like H2. What H2 does: {code:java} H2TreeIndex:: getRowCount() public long InlineIndexImpl::count(int segment, IndexQueryContext qryCtx) throws IgniteCheckedException { return segments[segment].size(filterClosure(qryCtx)); } metaPage -> records number {code} Calcite: IgniteReduceHashAggregate(group=[{}], COUNT(*)=[COUNT()]) IgniteExchange(distribution=[single]) IgniteMapHashAggregate(group=[{}], COUNT(*)=[COUNT()]) IgniteTableScan(table=[[PUBLIC, PI_COM_DAY]]) > Calcite Engine. COUNT() lacks optimization. > ------------------------------------------- > > Key: IGNITE-16920 > URL: https://issues.apache.org/jira/browse/IGNITE-16920 > Project: Ignite > Issue Type: Improvement > Components: sql > Affects Versions: 2.13 > Reporter: YuJue Li > Priority: Major > Labels: calcite2-required, calcite3-required > Fix For: 2.14 > > Attachments: PI_COM_DAY.sql, example-calcite.xml, > image-2022-05-01-13-35-59-275.png > > > !image-2022-05-01-13-35-59-275.png! -- This message was sent by Atlassian Jira (v8.20.7#820007)