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ASF GitHub Bot commented on TRAFODION-2520: ------------------------------------------- Github user zellerh commented on a diff in the pull request: https://github.com/apache/incubator-trafodion/pull/990#discussion_r104524268 --- Diff: docs/sql_reference/src/asciidoc/_chapters/olap_functions.adoc --- @@ -26,8 +26,20 @@ [[olap_functions]] = OLAP Functions -This section describes the syntax and semantics of the On Line -Analytical Process (OLAP) window functions. The OLAP window functions +On-line Analytical Process (OLAP) functions provide the capability to partition source data into groups of rows, order the rows in each group, compute aggregates within a window frame for a row. Typically, an OLAP function in SQL is expressed in two components <FUNCTION> and <OVER>: <FUNCTION> specifies the function and the arguments, and <OVER> specifies the partitioning, the ordering and the window frames. <OVER> is sometimes called the window. OLAP functions are used to perform analytic tasks against data sets stored in or computed from a set of tables, such as moving average and ranks. + +Trafodion also supports a set of sequence functions which are SQL extensions and have to be used together with a SEQUENCE BY clause. These sequence functions can be used to compute a running quantity of a column up to and include the current row as follows. --- End diff -- Would it make sense to list those functions under a separate heading, so it is clear that they are not confused with the ANSI SQL OLAP functions? Maybe also give an example? > Add details for OLAP function + Add LEAD, LAG, FIRST_VALUE & LAST_VALUE > window functions > ---------------------------------------------------------------------------------------- > > Key: TRAFODION-2520 > URL: https://issues.apache.org/jira/browse/TRAFODION-2520 > Project: Apache Trafodion > Issue Type: Documentation > Reporter: Liu Yu > Assignee: Liu Yu > -- This message was sent by Atlassian JIRA (v6.3.15#6346)