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ASF GitHub Bot commented on DRILL-7199: --------------------------------------- amansinha100 commented on pull request #1771: DRILL-7199: Optimize population of metadata for non-interesting columns URL: https://github.com/apache/drill/pull/1771#discussion_r280187957 ########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/physical/base/AbstractGroupScanWithMetadata.java ########## @@ -146,15 +148,23 @@ public boolean isMatchAllMetadata() { */ @Override public long getColumnValueCount(SchemaPath column) { - long tableRowCount = (long) TableStatisticsKind.ROW_COUNT.getValue(getTableMetadata()); + long tableRowCount, colNulls; + Long nulls; ColumnStatistics columnStats = getTableMetadata().getColumnStatistics(column); - long colNulls; + ColumnStatistics nonInterestingColStats = getNonInterestingColumnsMetadata().getColumnStatistics(column); + if (columnStats != null) { - Long nulls = (Long) columnStats.getStatistic(ColumnStatisticsKind.NULLS_COUNT); - colNulls = nulls != null ? nulls : GroupScan.NO_COLUMN_STATS; + tableRowCount = (long) TableStatisticsKind.ROW_COUNT.getValue(getTableMetadata()); + } else if (nonInterestingColStats != null) { Review comment: Since only one of `columnStats` (btw, let's call it `interestingColStats` to be consistent) or `nonInterestingColStats` will be non-null, we should ideally invoke `getNonInterestingColumnsMetadata()` only if the `columnStats` is null...otherwise the second call is redundant. So, something like: `ColumnStatistics interestingColStats = getTableMetadata().getColumnStatistics(column);` `ColumnStatistics nonInterestingColStats = null;` `if (interestingColStats == null) {` `nonInterestingColStats = getNonInterestingColumnsMetadata().getColumnStatistics(column);` `}` Also, for the last `else` case, add a comment that the `return 0` is for non-existing columns. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org > Optimize the time taken to populate column statistics for non-interesting > columns > --------------------------------------------------------------------------------- > > Key: DRILL-7199 > URL: https://issues.apache.org/jira/browse/DRILL-7199 > Project: Apache Drill > Issue Type: Bug > Reporter: Venkata Jyothsna Donapati > Assignee: Venkata Jyothsna Donapati > Priority: Minor > Fix For: 1.17.0 > > Original Estimate: 48h > Remaining Estimate: 48h > > Currently populating column statistics for non-interesting columns very long > since it is populated for every row group. Since non-interesting column > statistics are common for the table, it can be populated once and can be > reused. -- This message was sent by Atlassian JIRA (v7.6.3#76005)