snuyanzin commented on code in PR #4984: URL: https://github.com/apache/calcite/pull/4984#discussion_r3364360617
########## site/_docs/reference.md: ########## @@ -2318,6 +2318,61 @@ each row in the original table to a window. The output table has all the same columns as the original table plus two additional columns `window_start` and `window_end`, which represent the start and end of the window interval, respectively. +#### Polymorphic table functions + +A polymorphic table function (PTF) is a table function that takes one or more +*table arguments* in addition to scalar and `DESCRIPTOR` arguments. Like any +table function, it is invoked in the `FROM` clause; the examples below place the +call inside the `TABLE( ... )` operator, as in `SELECT * FROM TABLE(funcName(...))`, +which is the form used by the SQL standard, but Calcite also accepts the implicit +form `SELECT * FROM funcName(...)`. + +A table argument is introduced by the `TABLE` keyword and is either a table +reference or a query. A table argument with set semantics may be followed by a +`PARTITION BY` clause, an `ORDER BY` clause, or both; each partition is then +processed independently. A table argument with row semantics may not be +partitioned or ordered. + +A PTF may have more than one table argument, each with its own semantics, +partitioning and ordering; at most one of them may have row semantics. + +| Operator syntax | Description Review Comment: no, it is optional here in reference just because of symmetry -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
