From cc323df48e7ccd50dae97419430741acd6eba24d Mon Sep 17 00:00:00 2001 From: Matheus Alcantara Date: Wed, 4 Jun 2025 15:56:59 -0300 Subject: [PATCH v0] QUALIFY clause --- src/backend/optimizer/plan/planner.c | 5 ++ src/backend/parser/analyze.c | 8 +- src/backend/parser/gram.y | 21 +++-- src/backend/parser/parse_agg.c | 7 +- src/backend/parser/parse_clause.c | 57 +++++++++++- src/backend/parser/parse_expr.c | 4 + src/backend/parser/parse_func.c | 3 + src/backend/parser/parse_relation.c | 18 ++++ src/include/nodes/parsenodes.h | 5 ++ src/include/parser/kwlist.h | 1 + src/include/parser/parse_clause.h | 5 +- src/include/parser/parse_node.h | 3 + src/test/regress/expected/window.out | 125 +++++++++++++++++++++++++++ src/test/regress/sql/window.sql | 51 +++++++++++ 14 files changed, 300 insertions(+), 13 deletions(-) diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 549aedcfa99..1a8fb387e47 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -4710,6 +4710,11 @@ create_one_window_path(PlannerInfo *root, if (!topwindow) topqual = lappend(topqual, opexpr); } + + /*  Add QUALIFY qual */ + if (wc->qualifyQual != NULL) + topqual = lappend(topqual, (Expr *) wc->qualifyQual); + } path = (Path *) diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index 34f7c17f576..dd27fd3730b 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -1481,9 +1481,12 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt) qry->limitOption = stmt->limitOption; /* transform window clauses after we have seen all window functions */ + pstate->p_targetList = qry->targetList; qry->windowClause = transformWindowDefinitions(pstate, pstate->p_windowdefs, - &qry->targetList); + &qry->targetList, + stmt->qualifyClause); + /* resolve any still-unresolved output columns as being type text */ if (pstate->p_resolve_unknowns) @@ -2975,7 +2978,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt) /* transform window clauses after we have seen all window functions */ qry->windowClause = transformWindowDefinitions(pstate, pstate->p_windowdefs, - &qry->targetList); + &qry->targetList, + NULL); /* FIXME(matheus) */ qry->rtable = pstate->p_rtable; qry->rteperminfos = pstate->p_rteperminfos; diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 73345bb3c70..63c0da99256 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -520,7 +520,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); %type TableElement TypedTableElement ConstraintElem DomainConstraintElem TableFuncElement %type columnDef columnOptions optionalPeriodName %type def_elem reloption_elem old_aggr_elem operator_def_elem -%type def_arg columnElem where_clause where_or_current_clause +%type def_arg columnElem where_clause qualify_clause where_or_current_clause a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound columnref having_clause func_table xmltable array_expr OptWhereClause operator_def_arg @@ -760,7 +760,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); POSITION PRECEDING PRECISION PRESERVE PREPARE PREPARED PRIMARY PRIOR PRIVILEGES PROCEDURAL PROCEDURE PROCEDURES PROGRAM PUBLICATION - QUOTE QUOTES + QUALIFY QUOTE QUOTES RANGE READ REAL REASSIGN RECURSIVE REF_P REFERENCES REFERENCING REFRESH REINDEX RELATIVE_P RELEASE RENAME REPEATABLE REPLACE REPLICA @@ -12993,7 +12993,7 @@ select_clause: */ simple_select: SELECT opt_all_clause opt_target_list - into_clause from_clause where_clause + into_clause from_clause where_clause qualify_clause group_clause having_clause window_clause { SelectStmt *n = makeNode(SelectStmt); @@ -13002,10 +13002,11 @@ simple_select: n->intoClause = $4; n->fromClause = $5; n->whereClause = $6; - n->groupClause = ($7)->list; - n->groupDistinct = ($7)->distinct; - n->havingClause = $8; - n->windowClause = $9; + n->qualifyClause = $7; + n->groupClause = ($8)->list; + n->groupDistinct = ($8)->distinct; + n->havingClause = $9; + n->windowClause = $10; $$ = (Node *) n; } | SELECT distinct_clause target_list @@ -14135,6 +14136,11 @@ where_clause: | /*EMPTY*/ { $$ = NULL; } ; +qualify_clause: + QUALIFY a_expr { $$ = $2; } + | /*EMPTY*/ { $$ = NULL; } + ; + /* variant for UPDATE and DELETE */ where_or_current_clause: WHERE a_expr { $$ = $2; } @@ -18250,6 +18256,7 @@ reserved_keyword: | ORDER | PLACING | PRIMARY + | QUALIFY | REFERENCES | RETURNING | SELECT diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index 0ac8966e30f..deeb3584f97 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -402,6 +402,9 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr) case EXPR_KIND_WHERE: errkind = true; break; + case EXPR_KIND_QUALIFY: + errkind = true; + break; case EXPR_KIND_POLICY: if (isAgg) err = _("aggregate functions are not allowed in policy expressions"); @@ -878,8 +881,6 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc, case EXPR_KIND_WHERE: errkind = true; break; - case EXPR_KIND_POLICY: - err = _("window functions are not allowed in policy expressions"); break; case EXPR_KIND_HAVING: errkind = true; @@ -895,6 +896,8 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc, err = _("window functions are not allowed in window definitions"); break; case EXPR_KIND_SELECT_TARGET: + case EXPR_KIND_POLICY: + case EXPR_KIND_QUALIFY: /* okay */ break; case EXPR_KIND_INSERT_TARGET: diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index 9f20a70ce13..75f5ab727f9 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -1842,6 +1842,51 @@ setNamespaceLateralState(List *namespace, bool lateral_only, bool lateral_ok) } } +Node * +transformQualifyClause(ParseState *pstate, List *targetlist, Node *qualify) +{ + Node *where; + + if (qualify == NULL) + return NULL; + + where = transformWhereClause(pstate, + qualify, + EXPR_KIND_QUALIFY, + "QUALIFY"); + + /* + *  Transform any Var referencing a WindowFunc into a real WindowFunc de + * fact. + */ + if (IsA(where, OpExpr)) + { + ListCell *lc; + OpExpr *op = (OpExpr *) where; + List *newArgs = NIL; + + foreach(lc, op->args) + { + Node *node = lfirst(lc); + + if (IsA(node, Var)) + { + Var *var = (Var *) node; + TargetEntry *tle = (TargetEntry *) lfirst(&targetlist->elements[var->varattno - 1]); + + + Assert(IsA(tle->expr, WindowFunc)); + newArgs = lappend(newArgs, (Node *) tle->expr); + } + else + newArgs = lappend(newArgs, node); + } + op->args = newArgs; + } + + return where; +} + /* * transformWhereClause - @@ -2764,7 +2809,8 @@ transformSortClause(ParseState *pstate, List * transformWindowDefinitions(ParseState *pstate, List *windowdefs, - List **targetlist) + List **targetlist, + Node *qualify) { List *result = NIL; Index winref = 0; @@ -2776,6 +2822,7 @@ transformWindowDefinitions(ParseState *pstate, WindowClause *refwc = NULL; List *partitionClause; List *orderClause; + Node *qualifyClause; Oid rangeopfamily = InvalidOid; Oid rangeopcintype = InvalidOid; WindowClause *wc; @@ -2824,12 +2871,20 @@ transformWindowDefinitions(ParseState *pstate, EXPR_KIND_WINDOW_PARTITION, true /* force SQL99 rules */ ); + /* + * transform QUALIFY. targetlist is used find the window function + * reference. + * + */ + qualifyClause = transformQualifyClause(pstate, *targetlist, qualify); + /* * And prepare the new WindowClause. */ wc = makeNode(WindowClause); wc->name = windef->name; wc->refname = windef->refname; + wc->qualifyQual = qualifyClause; /* * Per spec, a windowdef that references a previous one copies the diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index d66276801c6..d30661e8da5 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -575,6 +575,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref) case EXPR_KIND_COPY_WHERE: case EXPR_KIND_GENERATED_COLUMN: case EXPR_KIND_CYCLE_MARK: + case EXPR_KIND_QUALIFY: /* okay */ break; @@ -1794,6 +1795,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink) case EXPR_KIND_FROM_SUBSELECT: case EXPR_KIND_FROM_FUNCTION: case EXPR_KIND_WHERE: + case EXPR_KIND_QUALIFY: case EXPR_KIND_POLICY: case EXPR_KIND_HAVING: case EXPR_KIND_FILTER: @@ -3219,6 +3221,8 @@ ParseExprKindName(ParseExprKind exprKind) return "GENERATED AS"; case EXPR_KIND_CYCLE_MARK: return "CYCLE"; + case EXPR_KIND_QUALIFY: + return "QUALIFY"; /* * There is intentionally no default: case here, so that the diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c index 583bbbf232f..4e202949bfd 100644 --- a/src/backend/parser/parse_func.c +++ b/src/backend/parser/parse_func.c @@ -2557,6 +2557,9 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location) case EXPR_KIND_WHERE: errkind = true; break; + case EXPR_KIND_QUALIFY: + errkind = true; + break; case EXPR_KIND_POLICY: err = _("set-returning functions are not allowed in policy expressions"); break; diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c index 04ecf64b1fc..d3bb9346dec 100644 --- a/src/backend/parser/parse_relation.c +++ b/src/backend/parser/parse_relation.c @@ -922,6 +922,24 @@ colNameToVar(ParseState *pstate, const char *colname, bool localonly, newresult = scanNSItemForColumn(orig_pstate, nsitem, sublevels_up, colname, location); + /* + * If we are parsing a QUALIFY expression try to search the window + * function reference on target list + */ + if (newresult == NULL && orig_pstate->p_hasWindowFuncs + && pstate->p_expr_kind == EXPR_KIND_QUALIFY) + { + ListCell *lc; + + foreach(lc, pstate->p_targetList) + { + TargetEntry *tle = (TargetEntry *) lfirst(lc); + + if (strcmp(tle->resname, colname) == 0) + newresult = (Node *) makeVarFromTargetEntry(OUTER_VAR, tle); + } + } + if (newresult) { if (result) diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index 86a236bd58b..824b7238ca9 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -220,6 +220,8 @@ typedef struct Query Node *havingQual; /* qualifications applied to groups */ + Node *qualifyQual; /* qualifications applied to window functions */ + List *windowClause; /* a list of WindowClause's */ List *distinctClause; /* a list of SortGroupClause's */ @@ -1575,6 +1577,8 @@ typedef struct WindowClause int frameOptions; /* frame_clause options, see WindowDef */ Node *startOffset; /* expression for starting bound, if any */ Node *endOffset; /* expression for ending bound, if any */ + /* QUALIFY clause */ + Node *qualifyQual; /* in_range function for startOffset */ Oid startInRangeFunc pg_node_attr(query_jumble_ignore); /* in_range function for endOffset */ @@ -2190,6 +2194,7 @@ typedef struct SelectStmt List *targetList; /* the target list (of ResTarget) */ List *fromClause; /* the FROM clause */ Node *whereClause; /* WHERE qualification */ + Node *qualifyClause; /* QUALIFY qualification */ List *groupClause; /* GROUP BY clauses */ bool groupDistinct; /* Is this GROUP BY DISTINCT? */ Node *havingClause; /* HAVING conditional-expression */ diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h index a4af3f717a1..f7e267dd241 100644 --- a/src/include/parser/kwlist.h +++ b/src/include/parser/kwlist.h @@ -359,6 +359,7 @@ PG_KEYWORD("procedure", PROCEDURE, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("procedures", PROCEDURES, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("program", PROGRAM, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("publication", PUBLICATION, UNRESERVED_KEYWORD, BARE_LABEL) +PG_KEYWORD("qualify", QUALIFY, RESERVED_KEYWORD, AS_LABEL) PG_KEYWORD("quote", QUOTE, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("quotes", QUOTES, UNRESERVED_KEYWORD, BARE_LABEL) PG_KEYWORD("range", RANGE, UNRESERVED_KEYWORD, BARE_LABEL) diff --git a/src/include/parser/parse_clause.h b/src/include/parser/parse_clause.h index 3e9894926de..5580842ee33 100644 --- a/src/include/parser/parse_clause.h +++ b/src/include/parser/parse_clause.h @@ -20,6 +20,8 @@ extern void transformFromClause(ParseState *pstate, List *frmList); extern int setTargetTable(ParseState *pstate, RangeVar *relation, bool inh, bool alsoSource, AclMode requiredPerms); + +extern Node * transformQualifyClause(ParseState *pstate, List *targetlist, Node *qualify); extern Node *transformWhereClause(ParseState *pstate, Node *clause, ParseExprKind exprKind, const char *constructName); extern Node *transformLimitClause(ParseState *pstate, Node *clause, @@ -35,7 +37,8 @@ extern List *transformSortClause(ParseState *pstate, List *orderlist, extern List *transformWindowDefinitions(ParseState *pstate, List *windowdefs, - List **targetlist); + List **targetlist, + Node *qualify); extern List *transformDistinctClause(ParseState *pstate, List **targetlist, List *sortClause, bool is_agg); diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h index f7d07c84542..05f0f17ba3d 100644 --- a/src/include/parser/parse_node.h +++ b/src/include/parser/parse_node.h @@ -45,6 +45,7 @@ typedef enum ParseExprKind EXPR_KIND_FROM_FUNCTION, /* function in FROM clause */ EXPR_KIND_WHERE, /* WHERE */ EXPR_KIND_HAVING, /* HAVING */ + EXPR_KIND_QUALIFY, /* QUALIFY */ EXPR_KIND_FILTER, /* FILTER */ EXPR_KIND_WINDOW_PARTITION, /* window definition PARTITION BY */ EXPR_KIND_WINDOW_ORDER, /* window definition ORDER BY */ @@ -231,6 +232,8 @@ struct ParseState Node *p_last_srf; /* most recent set-returning func/op found */ + List *p_targetList; /* target list (of TargetEntry) */ + /* * Optional hook functions for parser callbacks. These are null unless * set up by the caller of make_parsestate. diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out index b86b668f433..5c886c06141 100644 --- a/src/test/regress/expected/window.out +++ b/src/test/regress/expected/window.out @@ -4537,6 +4537,131 @@ WHERE first_emp = 1 OR last_emp = 1; sales | 4 | 4800 | 08-08-2007 | 3 | 1 (6 rows) +-- Test QUALIFY clause +SELECT *, + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY RANK() OVER (PARTITION BY depname ORDER BY salary DESC) <= 2; + depname | empno | salary | enroll_date | rank +-----------+-------+--------+-------------+------ + develop | 8 | 6000 | 10-01-2006 | 1 + develop | 10 | 5200 | 08-01-2007 | 2 + develop | 11 | 5200 | 08-15-2007 | 2 + personnel | 2 | 3900 | 12-23-2006 | 1 + personnel | 5 | 3500 | 12-10-2007 | 2 + sales | 1 | 5000 | 10-01-2006 | 1 + sales | 4 | 4800 | 08-08-2007 | 2 + sales | 3 | 4800 | 08-01-2007 | 2 +(8 rows) + +SELECT *, + ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date DESC) +FROM empsalary +QUALIFY ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date DESC) = 1; + depname | empno | salary | enroll_date | row_number +-----------+-------+--------+-------------+------------ + develop | 7 | 4200 | 01-01-2008 | 1 + personnel | 5 | 3500 | 12-10-2007 | 1 + sales | 4 | 4800 | 08-08-2007 | 1 +(3 rows) + +SELECT *, + AVG(salary) OVER (PARTITION BY depname) AS avg_salary +FROM empsalary +QUALIFY salary > avg_salary; + depname | empno | salary | enroll_date | avg_salary +-----------+-------+--------+-------------+----------------------- + develop | 11 | 5200 | 08-15-2007 | 5020.0000000000000000 + develop | 8 | 6000 | 10-01-2006 | 5020.0000000000000000 + develop | 10 | 5200 | 08-01-2007 | 5020.0000000000000000 + personnel | 2 | 3900 | 12-23-2006 | 3700.0000000000000000 + sales | 1 | 5000 | 10-01-2006 | 4866.6666666666666667 +(5 rows) + +SELECT *, + COUNT(*) OVER (PARTITION BY depname, salary) +FROM empsalary +QUALIFY COUNT(*) OVER (PARTITION BY depname, salary) = 1; + depname | empno | salary | enroll_date | count +-----------+-------+--------+-------------+------- + develop | 7 | 4200 | 01-01-2008 | 1 + develop | 9 | 4500 | 01-01-2008 | 1 + develop | 8 | 6000 | 10-01-2006 | 1 + personnel | 5 | 3500 | 12-10-2007 | 1 + personnel | 2 | 3900 | 12-23-2006 | 1 + sales | 1 | 5000 | 10-01-2006 | 1 +(6 rows) + +SELECT *, + RANK() OVER (ORDER BY salary DESC) as rank +FROM empsalary +QUALIFY rank = 2; + depname | empno | salary | enroll_date | rank +---------+-------+--------+-------------+------ + develop | 10 | 5200 | 08-01-2007 | 2 + develop | 11 | 5200 | 08-15-2007 | 2 +(2 rows) + +SELECT *, + ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date) +FROM empsalary +QUALIFY ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date) <= 3; + depname | empno | salary | enroll_date | row_number +-----------+-------+--------+-------------+------------ + develop | 8 | 6000 | 10-01-2006 | 1 + develop | 10 | 5200 | 08-01-2007 | 2 + develop | 11 | 5200 | 08-15-2007 | 3 + personnel | 2 | 3900 | 12-23-2006 | 1 + personnel | 5 | 3500 | 12-10-2007 | 2 + sales | 1 | 5000 | 10-01-2006 | 1 + sales | 3 | 4800 | 08-01-2007 | 2 + sales | 4 | 4800 | 08-08-2007 | 3 +(8 rows) + +SELECT *, + ROW_NUMBER() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY ROW_NUMBER() OVER (PARTITION BY depname ORDER BY salary DESC) <= 2 +ORDER BY depname, salary DESC; + depname | empno | salary | enroll_date | row_number +-----------+-------+--------+-------------+------------ + develop | 8 | 6000 | 10-01-2006 | 1 + develop | 10 | 5200 | 08-01-2007 | 2 + personnel | 2 | 3900 | 12-23-2006 | 1 + personnel | 5 | 3500 | 12-10-2007 | 2 + sales | 1 | 5000 | 10-01-2006 | 1 + sales | 4 | 4800 | 08-08-2007 | 2 +(6 rows) + +SELECT *, + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) <= 2 + AND enroll_date > DATE '2007-01-01'; + depname | empno | salary | enroll_date | rank +-----------+-------+--------+-------------+------ + develop | 10 | 5200 | 08-01-2007 | 2 + develop | 11 | 5200 | 08-15-2007 | 2 + personnel | 5 | 3500 | 12-10-2007 | 2 + sales | 4 | 4800 | 08-08-2007 | 2 + sales | 3 | 4800 | 08-01-2007 | 2 +(5 rows) + +SELECT *, + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) = 1 + OR salary < 4000; + depname | empno | salary | enroll_date | rank +-----------+-------+--------+-------------+------ + develop | 8 | 6000 | 10-01-2006 | 1 + personnel | 2 | 3900 | 12-23-2006 | 1 + personnel | 5 | 3500 | 12-10-2007 | 2 + sales | 1 | 5000 | 10-01-2006 | 1 +(4 rows) + -- cleanup DROP TABLE empsalary; -- test user-defined window function with named args and default args diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql index 02f105f070e..4f376d1b459 100644 --- a/src/test/regress/sql/window.sql +++ b/src/test/regress/sql/window.sql @@ -1522,6 +1522,57 @@ SELECT * FROM FROM empsalary) emp WHERE first_emp = 1 OR last_emp = 1; +-- Test QUALIFY clause +SELECT *, + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY RANK() OVER (PARTITION BY depname ORDER BY salary DESC) <= 2; + +SELECT *, + ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date DESC) +FROM empsalary +QUALIFY ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date DESC) = 1; + +SELECT *, + AVG(salary) OVER (PARTITION BY depname) AS avg_salary +FROM empsalary +QUALIFY salary > avg_salary; + +SELECT *, + COUNT(*) OVER (PARTITION BY depname, salary) +FROM empsalary +QUALIFY COUNT(*) OVER (PARTITION BY depname, salary) = 1; + +SELECT *, + RANK() OVER (ORDER BY salary DESC) as rank +FROM empsalary +QUALIFY rank = 2; + +SELECT *, + ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date) +FROM empsalary +QUALIFY ROW_NUMBER() OVER (PARTITION BY depname ORDER BY enroll_date) <= 3; + +SELECT *, + ROW_NUMBER() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY ROW_NUMBER() OVER (PARTITION BY depname ORDER BY salary DESC) <= 2 +ORDER BY depname, salary DESC; + +SELECT *, + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) <= 2 + AND enroll_date > DATE '2007-01-01'; + +SELECT *, + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) +FROM empsalary +QUALIFY + RANK() OVER (PARTITION BY depname ORDER BY salary DESC) = 1 + OR salary < 4000; + -- cleanup DROP TABLE empsalary; -- 2.39.5 (Apple Git-154)