[jira] [Commented] (CALCITE-5940) Add the Rule to merge Limit
[ https://issues.apache.org/jira/browse/CALCITE-5940?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17769535#comment-17769535 ] Jiajun Xie commented on CALCITE-5940: - Fixed in [aef9bdb|https://github.com/apache/calcite/commit/aef9bdb5c091e4df84eeb47a9aa70770dd3d3fb8]. Thanks for your PR [~shenlang]. Thanks for your review [~kgyrtkirk] , [~nobigo], [~taoran]. > Add the Rule to merge Limit > --- > > Key: CALCITE-5940 > URL: https://issues.apache.org/jira/browse/CALCITE-5940 > Project: Calcite > Issue Type: New Feature >Reporter: LakeShen >Assignee: LakeShen >Priority: Major > Labels: pull-request-available > Fix For: 1.36.0 > > > Now in calcite,the Limit will be represented using > LogicalSort(fetch=[xx]),but there are few rules to optimize Limit. > In trino and presto,there are many optimization rules to optimize Limit. > For example,the sql: > {code:java} > select * from nation limit 0 {code} > The limit 0 will use empty ValuesNode(Calcite LogicalValues) to optimize,so > the SQL is not delivered to the Worker compute,the rule could see: > [EvaluateZeroLimit|https://github.com/prestodb/presto/blob/fea80c96ddfe4dc42f79c3cff9294b88595275ce/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/EvaluateZeroLimit.java#L28C1-L28C31] > The sql: > {code:java} > select concat('-',N_REGIONKEY) from (select * from nation limit 1) limit > 10 {code} > It would be optimized by > [MergeLimits|https://github.com/prestodb/presto/blob/fea80c96ddfe4dc42f79c3cff9294b88595275ce/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/MergeLimits.java#L26] > rule to: > {code:java} > select concat('-',N_REGIONKEY) from nation limit 10 {code} > The value of limit takes the minimum of the outer limit and the inner limit. > The sql: > {code:java} > select concat('-',N_REGIONKEY) from (SELECT * FROM nation order BY > N_REGIONKEY DESC LIMIT 1) limit 10 {code} > It would be optimized by > [MergeLimitWithTopN|https://github.com/prestodb/presto/blob/fea80c96ddfe4dc42f79c3cff9294b88595275ce/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/MergeLimitWithTopN.java#L28C1-L28C31] > rule to: > {code:java} > SELECT concat('-',N_REGIONKEY) FROM nation order BY N_REGIONKEY DESC LIMIT > 10{code} > So I propose to add these three rules to Calcite as well, to optimize the > Limit case. > > -- This message was sent by Atlassian Jira (v8.20.10#820010)
[jira] [Commented] (CALCITE-5940) Add the Rule to merge Limit
[ https://issues.apache.org/jira/browse/CALCITE-5940?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17769467#comment-17769467 ] LakeShen commented on CALCITE-5940: --- Hi [~jiajunbernoulli] ,thanks for your suggestions,I have done for it. > Add the Rule to merge Limit > --- > > Key: CALCITE-5940 > URL: https://issues.apache.org/jira/browse/CALCITE-5940 > Project: Calcite > Issue Type: New Feature >Reporter: LakeShen >Assignee: LakeShen >Priority: Major > Labels: pull-request-available > Fix For: 1.36.0 > > > Now in calcite,the Limit will be represented using > LogicalSort(fetch=[xx]),but there are few rules to optimize Limit. > In trino and presto,there are many optimization rules to optimize Limit. > For example,the sql: > {code:java} > select * from nation limit 0 {code} > The limit 0 will use empty ValuesNode(Calcite LogicalValues) to optimize,so > the SQL is not delivered to the Worker compute,the rule could see: > [EvaluateZeroLimit|https://github.com/prestodb/presto/blob/fea80c96ddfe4dc42f79c3cff9294b88595275ce/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/EvaluateZeroLimit.java#L28C1-L28C31] > The sql: > {code:java} > select concat('-',N_REGIONKEY) from (select * from nation limit 1) limit > 10 {code} > It would be optimized by > [MergeLimits|https://github.com/prestodb/presto/blob/fea80c96ddfe4dc42f79c3cff9294b88595275ce/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/MergeLimits.java#L26] > rule to: > {code:java} > select concat('-',N_REGIONKEY) from nation limit 10 {code} > The value of limit takes the minimum of the outer limit and the inner limit. > The sql: > {code:java} > select concat('-',N_REGIONKEY) from (SELECT * FROM nation order BY > N_REGIONKEY DESC LIMIT 1) limit 10 {code} > It would be optimized by > [MergeLimitWithTopN|https://github.com/prestodb/presto/blob/fea80c96ddfe4dc42f79c3cff9294b88595275ce/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/MergeLimitWithTopN.java#L28C1-L28C31] > rule to: > {code:java} > SELECT concat('-',N_REGIONKEY) FROM nation order BY N_REGIONKEY DESC LIMIT > 10{code} > So I propose to add these three rules to Calcite as well, to optimize the > Limit case. > > -- This message was sent by Atlassian Jira (v8.20.10#820010)