static int32 qsort_partition_rbound_cmp(const void *a, const void *b,
void *arg);
-static List *get_qual_for_list(PartitionKey key, PartitionBoundSpec *spec);
-static List *get_qual_for_range(PartitionKey key, PartitionBoundSpec *spec);
static Oid get_partition_operator(PartitionKey key, int col,
StrategyNumber strategy, bool *need_relabel);
+static Expr *make_partition_op_expr(PartitionKey key, int keynum,
+ uint16 strategy, Expr *arg1, Expr *arg2);
+static void get_range_key_properties(PartitionKey key, int keynum,
+ PartitionRangeDatum *ldatum,
+ PartitionRangeDatum *udatum,
+ ListCell **partexprs_item,
+ Expr **keyCol,
+ Const **lower_val, Const **upper_val);
+static List *get_qual_for_list(PartitionKey key, PartitionBoundSpec *spec);
+static List *get_qual_for_range(PartitionKey key, PartitionBoundSpec *spec);
static List *generate_partition_qual(Relation rel);
static PartitionRangeBound *make_one_range_bound(PartitionKey key, int index,
/* Module-local functions */
+/*
+ * get_partition_operator
+ *
+ * Return oid of the operator of given strategy for a given partition key
+ * column.
+ */
+static Oid
+get_partition_operator(PartitionKey key, int col, StrategyNumber strategy,
+ bool *need_relabel)
+{
+ Oid operoid;
+
+ /*
+ * First check if there exists an operator of the given strategy, with
+ * this column's type as both its lefttype and righttype, in the
+ * partitioning operator family specified for the column.
+ */
+ operoid = get_opfamily_member(key->partopfamily[col],
+ key->parttypid[col],
+ key->parttypid[col],
+ strategy);
+
+ /*
+ * If one doesn't exist, we must resort to using an operator in the same
+ * opreator family but with the operator class declared input type. It is
+ * OK to do so, because the column's type is known to be binary-coercible
+ * with the operator class input type (otherwise, the operator class in
+ * question would not have been accepted as the partitioning operator
+ * class). We must however inform the caller to wrap the non-Const
+ * expression with a RelabelType node to denote the implicit coercion. It
+ * ensures that the resulting expression structurally matches similarly
+ * processed expressions within the optimizer.
+ */
+ if (!OidIsValid(operoid))
+ {
+ operoid = get_opfamily_member(key->partopfamily[col],
+ key->partopcintype[col],
+ key->partopcintype[col],
+ strategy);
+ *need_relabel = true;
+ }
+ else
+ *need_relabel = false;
+
+ if (!OidIsValid(operoid))
+ elog(ERROR, "could not find operator for partitioning");
+
+ return operoid;
+}
+
+/*
+ * make_partition_op_expr
+ * Returns an Expr for the given partition key column with arg1 and
+ * arg2 as its leftop and rightop, respectively
+ */
+static Expr *
+make_partition_op_expr(PartitionKey key, int keynum,
+ uint16 strategy, Expr *arg1, Expr *arg2)
+{
+ Oid operoid;
+ bool need_relabel = false;
+ Expr *result = NULL;
+
+ /* Get the correct btree operator for this partitioning column */
+ operoid = get_partition_operator(key, keynum, strategy, &need_relabel);
+
+ /*
+ * Chosen operator may be such that the non-Const operand needs to be
+ * coerced, so apply the same; see the comment in
+ * get_partition_operator().
+ */
+ if (!IsA(arg1, Const) &&
+ (need_relabel ||
+ key->partcollation[keynum] != key->parttypcoll[keynum]))
+ arg1 = (Expr *) makeRelabelType(arg1,
+ key->partopcintype[keynum],
+ -1,
+ key->partcollation[keynum],
+ COERCE_EXPLICIT_CAST);
+
+ /* Generate the actual expression */
+ switch (key->strategy)
+ {
+ case PARTITION_STRATEGY_LIST:
+ {
+ ScalarArrayOpExpr *saopexpr;
+
+ /* Build leftop = ANY (rightop) */
+ saopexpr = makeNode(ScalarArrayOpExpr);
+ saopexpr->opno = operoid;
+ saopexpr->opfuncid = get_opcode(operoid);
+ saopexpr->useOr = true;
+ saopexpr->inputcollid = key->partcollation[0];
+ saopexpr->args = list_make2(arg1, arg2);
+ saopexpr->location = -1;
+
+ result = (Expr *) saopexpr;
+ break;
+ }
+
+ case PARTITION_STRATEGY_RANGE:
+ result = make_opclause(operoid,
+ BOOLOID,
+ false,
+ arg1, arg2,
+ InvalidOid,
+ key->partcollation[keynum]);
+ break;
+
+ default:
+ elog(ERROR, "invalid partitioning strategy");
+ break;
+ }
+
+ return result;
+}
+
/*
* get_qual_for_list
*
{
List *result;
ArrayExpr *arr;
- ScalarArrayOpExpr *opexpr;
+ Expr *opexpr;
ListCell *cell,
*prev,
*next;
Expr *keyCol;
- Oid operoid;
- bool need_relabel,
- list_has_null = false;
+ bool list_has_null = false;
NullTest *nulltest1 = NULL,
*nulltest2 = NULL;
arr->multidims = false;
arr->location = -1;
- /* Get the correct btree equality operator */
- operoid = get_partition_operator(key, 0, BTEqualStrategyNumber,
- &need_relabel);
- if (need_relabel || key->partcollation[0] != key->parttypcoll[0])
- keyCol = (Expr *) makeRelabelType(keyCol,
- key->partopcintype[0],
- -1,
- key->partcollation[0],
- COERCE_EXPLICIT_CAST);
-
- /* Build leftop = ANY (rightop) */
- opexpr = makeNode(ScalarArrayOpExpr);
- opexpr->opno = operoid;
- opexpr->opfuncid = get_opcode(operoid);
- opexpr->useOr = true;
- opexpr->inputcollid = key->partcollation[0];
- opexpr->args = list_make2(keyCol, arr);
- opexpr->location = -1;
+ /* Generate the main expression, i.e., keyCol = ANY (arr) */
+ opexpr = make_partition_op_expr(key, 0, BTEqualStrategyNumber,
+ keyCol, (Expr *) arr);
if (nulltest1)
result = list_make2(nulltest1, opexpr);
return result;
}
+/*
+ * get_range_key_properties
+ * Returns range partition key information for a given column
+ *
+ * On return, *partexprs_item points to the cell containing the next
+ * expression in the key->partexprs list, or NULL.
+ */
+static void
+get_range_key_properties(PartitionKey key, int keynum,
+ PartitionRangeDatum *ldatum,
+ PartitionRangeDatum *udatum,
+ ListCell **partexprs_item,
+ Expr **keyCol,
+ Const **lower_val, Const **upper_val)
+{
+ /* Partition key expression for this column */
+ if (key->partattrs[keynum] != 0)
+ {
+ *keyCol = (Expr *) makeVar(1,
+ key->partattrs[keynum],
+ key->parttypid[keynum],
+ key->parttypmod[keynum],
+ key->parttypcoll[keynum],
+ 0);
+ }
+ else
+ {
+ *keyCol = copyObject(lfirst(*partexprs_item));
+ *partexprs_item = lnext(*partexprs_item);
+ }
+
+ if (!ldatum->infinite)
+ *lower_val = (Const *) ldatum->value;
+ else
+ *lower_val = NULL;
+
+ if (!udatum->infinite)
+ *upper_val = (Const *) udatum->value;
+ else
+ *upper_val = NULL;
+}
+
/*
* get_qual_for_range
*
- * Get a list of OpExpr's to use as a range partition's constraint.
+ * Get a list of expressions to use as a range partition's constraint.
+ * If there are multiple expressions, they are to be considered implicitly
+ * ANDed.
+ *
+ * For a multi-column range partition key, say (a, b, c), with (al, bl, cl)
+ * as the lower bound tuple and (au, bu, cu) as the upper bound tuple, we
+ * generate an expression tree of the following form:
+ *
+ * (a > al OR (a = al AND b > bl) OR (a = al AND b = bl AND c >= cl))
+ * AND
+ * (a < au OR (a = au AND b < bu) OR (a = au AND b = bu AND c < cu))
+ *
+ * If, say, b were an expression key instead of a simple column, we also
+ * append (b IS NOT NULL) to the AND's argument list.
+ *
+ * It is often the case that a prefix of lower and upper bound tuples contains
+ * the same values, for example, (al = au), in which case, we will emit an
+ * expression tree of the following form:
+ *
+ * (a = al)
+ * AND
+ * (b > bl OR (b = bl AND c >= cl))
+ * AND
+ * (b < bu) OR (b = bu AND c < cu))
+ *
+ * If cu happens to be UNBOUNDED, we need not emit any expression for it, so
+ * the last line would be:
+ *
+ * (b < bu) OR (b = bu), which is simplified to (b <= bu)
+ *
+ * In most common cases with only one partition column, say a, the following
+ * expression tree will be generated: a >= al AND a < au
+ *
+ * If all values of both lower and upper bounds are UNBOUNDED, the partition
+ * does not really have a constraint, except the IS NOT NULL constraint for
+ * any expression keys.
+ *
+ * If we end up with an empty result list, we append return a single-member
+ * list containing a constant-true expression in that case, because callers
+ * expect a non-empty list.
*/
static List *
get_qual_for_range(PartitionKey key, PartitionBoundSpec *spec)
List *result = NIL;
ListCell *cell1,
*cell2,
- *partexprs_item;
- int i;
+ *partexprs_item,
+ *partexprs_item_saved;
+ int i,
+ j;
+ PartitionRangeDatum *ldatum,
+ *udatum;
+ Expr *keyCol;
+ Const *lower_val,
+ *upper_val;
+ NullTest *nulltest;
+ List *lower_or_arms,
+ *upper_or_arms;
+ int num_or_arms,
+ current_or_arm;
+ ListCell *lower_or_start_datum,
+ *upper_or_start_datum;
+ bool need_next_lower_arm,
+ need_next_upper_arm;
+
+ lower_or_start_datum = list_head(spec->lowerdatums);
+ upper_or_start_datum = list_head(spec->upperdatums);
+ num_or_arms = key->partnatts;
/*
- * Iterate over columns of the key, emitting an OpExpr for each using the
- * corresponding lower and upper datums as constant operands.
+ * A range-partitioned table does not allow partition keys to be null. For
+ * simple columns, their NOT NULL constraint suffices for the enforcement
+ * of non-nullability. But for the expression keys, which are still
+ * nullable, we must emit a IS NOT NULL expression. Collect them in
+ * result first.
*/
- i = 0;
partexprs_item = list_head(key->partexprs);
- forboth(cell1, spec->lowerdatums, cell2, spec->upperdatums)
+ for (i = 0; i < key->partnatts; i++)
{
- PartitionRangeDatum *ldatum = lfirst(cell1),
- *udatum = lfirst(cell2);
- Expr *keyCol;
- Const *lower_val = NULL,
- *upper_val = NULL;
- EState *estate;
- MemoryContext oldcxt;
- Expr *test_expr;
- ExprState *test_exprstate;
- Datum test_result;
- bool isNull;
- bool need_relabel = false;
- Oid operoid;
- NullTest *nulltest;
-
- /* Left operand */
- if (key->partattrs[i] != 0)
- {
- keyCol = (Expr *) makeVar(1,
- key->partattrs[i],
- key->parttypid[i],
- key->parttypmod[i],
- key->parttypcoll[i],
- 0);
- }
- else
+ if (key->partattrs[i] == 0)
{
- keyCol = copyObject(lfirst(partexprs_item));
+ Expr *keyCol;
+
+ if (partexprs_item == NULL)
+ elog(ERROR, "wrong number of partition key expressions");
+ keyCol = lfirst(partexprs_item);
partexprs_item = lnext(partexprs_item);
- }
+ Assert(!IsA(keyCol, Var));
- /*
- * Emit a IS NOT NULL expression for non-Var keys, because whereas
- * simple attributes are covered by NOT NULL constraints, expression
- * keys are still nullable which is not acceptable in case of range
- * partitioning.
- */
- if (!IsA(keyCol, Var))
- {
nulltest = makeNode(NullTest);
nulltest->arg = keyCol;
nulltest->nulltesttype = IS_NOT_NULL;
nulltest->location = -1;
result = lappend(result, nulltest);
}
+ }
+
+ /*
+ * Iterate over the key columns and check if the corresponding lower and
+ * upper datums are equal using the btree equality operator for the
+ * column's type. If equal, we emit single keyCol = common_value
+ * expression. Starting from the first column for which the corresponding
+ * lower and upper bound datums are not equal, we generate OR expressions
+ * as shown in the function's header comment.
+ */
+ i = 0;
+ partexprs_item = list_head(key->partexprs);
+ forboth(cell1, spec->lowerdatums, cell2, spec->upperdatums)
+ {
+ EState *estate;
+ MemoryContext oldcxt;
+ Expr *test_expr;
+ ExprState *test_exprstate;
+ Datum test_result;
+ bool isNull;
+
+ ldatum = lfirst(cell1);
+ udatum = lfirst(cell2);
/*
- * Stop at this column if either of lower or upper datum is infinite,
- * but do emit an OpExpr for the non-infinite datum.
+ * Since get_range_key_properties() modifies partexprs_item, and we
+ * might need to start over from the previous expression in the later
+ * part of this functiom, save away the current value.
*/
- if (!ldatum->infinite)
- lower_val = (Const *) ldatum->value;
- if (!udatum->infinite)
- upper_val = (Const *) udatum->value;
+ partexprs_item_saved = partexprs_item;
+
+ get_range_key_properties(key, i, ldatum, udatum,
+ &partexprs_item,
+ &keyCol,
+ &lower_val, &upper_val);
/*
- * If lower_val and upper_val are both finite and happen to be equal,
- * emit only (keyCol = lower_val) for this column, because all rows in
- * this partition could only ever contain this value (ie, lower_val)
- * in the current partitioning column. We must consider further
- * columns because the above condition does not fully constrain the
- * rows of this partition.
+ * If either or both of lower_val and upper_val is NULL, they are
+ * unequal, because being NULL means the column is unbounded in the
+ * respective direction.
*/
- if (lower_val && upper_val)
- {
- /* Get the correct btree equality operator for the test */
- operoid = get_partition_operator(key, i, BTEqualStrategyNumber,
- &need_relabel);
-
- /* Create the test expression */
- estate = CreateExecutorState();
- oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
- test_expr = make_opclause(operoid,
- BOOLOID,
- false,
- (Expr *) lower_val,
- (Expr *) upper_val,
- InvalidOid,
- key->partcollation[i]);
- fix_opfuncids((Node *) test_expr);
- test_exprstate = ExecInitExpr(test_expr, NULL);
- test_result = ExecEvalExprSwitchContext(test_exprstate,
+ if (!lower_val || !upper_val)
+ break;
+
+ /* Create the test expression */
+ estate = CreateExecutorState();
+ oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
+ test_expr = make_partition_op_expr(key, i, BTEqualStrategyNumber,
+ (Expr *) lower_val,
+ (Expr *) upper_val);
+ fix_opfuncids((Node *) test_expr);
+ test_exprstate = ExecInitExpr(test_expr, NULL);
+ test_result = ExecEvalExprSwitchContext(test_exprstate,
GetPerTupleExprContext(estate),
- &isNull);
- MemoryContextSwitchTo(oldcxt);
- FreeExecutorState(estate);
+ &isNull);
+ MemoryContextSwitchTo(oldcxt);
+ FreeExecutorState(estate);
- if (DatumGetBool(test_result))
- {
- /* This can never be, but it's better to make sure */
- if (i == key->partnatts - 1)
- elog(ERROR, "invalid range bound specification");
-
- if (need_relabel || key->partcollation[i] != key->parttypcoll[i])
- keyCol = (Expr *) makeRelabelType(keyCol,
- key->partopcintype[i],
- -1,
- key->partcollation[i],
- COERCE_EXPLICIT_CAST);
- result = lappend(result,
- make_opclause(operoid,
- BOOLOID,
- false,
- keyCol,
- (Expr *) lower_val,
- InvalidOid,
- key->partcollation[i]));
-
- /* Go over to consider the next column. */
- i++;
- continue;
- }
- }
+ /* If not equal, go generate the OR expressions */
+ if (!DatumGetBool(test_result))
+ break;
/*
- * We can say here that lower_val != upper_val. Emit expressions
- * (keyCol >= lower_val) and (keyCol < upper_val), then stop.
+ * The bounds for the last key column can't be equal, because such a
+ * range partition would never be allowed to be defined (it would have
+ * an empty range otherwise).
*/
- if (lower_val)
- {
- operoid = get_partition_operator(key, i,
- BTGreaterEqualStrategyNumber,
- &need_relabel);
-
- if (need_relabel || key->partcollation[i] != key->parttypcoll[i])
- keyCol = (Expr *) makeRelabelType(keyCol,
- key->partopcintype[i],
- -1,
- key->partcollation[i],
- COERCE_EXPLICIT_CAST);
- result = lappend(result,
- make_opclause(operoid,
- BOOLOID,
- false,
- keyCol,
- (Expr *) lower_val,
- InvalidOid,
- key->partcollation[i]));
- }
+ if (i == key->partnatts - 1)
+ elog(ERROR, "invalid range bound specification");
- if (upper_val)
+ /* Equal, so generate keyCol = lower_val expression */
+ result = lappend(result,
+ make_partition_op_expr(key, i, BTEqualStrategyNumber,
+ keyCol, (Expr *) lower_val));
+
+ i++;
+ }
+
+ /* First pair of lower_val and upper_val that are not equal. */
+ lower_or_start_datum = cell1;
+ upper_or_start_datum = cell2;
+
+ /* OR will have as many arms as there are key columns left. */
+ num_or_arms = key->partnatts - i;
+ current_or_arm = 0;
+ lower_or_arms = upper_or_arms = NIL;
+ need_next_lower_arm = need_next_upper_arm = true;
+ while (current_or_arm < num_or_arms)
+ {
+ List *lower_or_arm_args = NIL,
+ *upper_or_arm_args = NIL;
+
+ j = i;
+ partexprs_item = partexprs_item_saved;
+
+ for_both_cell(cell1, lower_or_start_datum, cell2, upper_or_start_datum)
{
- operoid = get_partition_operator(key, i,
- BTLessStrategyNumber,
- &need_relabel);
-
- if (need_relabel || key->partcollation[i] != key->parttypcoll[i])
- keyCol = (Expr *) makeRelabelType(keyCol,
- key->partopcintype[i],
- -1,
- key->partcollation[i],
- COERCE_EXPLICIT_CAST);
-
- result = lappend(result,
- make_opclause(operoid,
- BOOLOID,
- false,
- keyCol,
- (Expr *) upper_val,
- InvalidOid,
- key->partcollation[i]));
+ PartitionRangeDatum *ldatum_next = NULL,
+ *udatum_next = NULL;
+
+ ldatum = lfirst(cell1);
+ if (lnext(cell1))
+ ldatum_next = lfirst(lnext(cell1));
+ udatum = lfirst(cell2);
+ if (lnext(cell2))
+ udatum_next = lfirst(lnext(cell2));
+ get_range_key_properties(key, j, ldatum, udatum,
+ &partexprs_item,
+ &keyCol,
+ &lower_val, &upper_val);
+
+ if (need_next_lower_arm && lower_val)
+ {
+ uint16 strategy;
+
+ /*
+ * For the non-last columns of this arm, use the EQ operator.
+ * For the last or the last finite-valued column, use GE.
+ */
+ if (j - i < current_or_arm)
+ strategy = BTEqualStrategyNumber;
+ else if ((ldatum_next && ldatum_next->infinite) ||
+ j == key->partnatts - 1)
+ strategy = BTGreaterEqualStrategyNumber;
+ else
+ strategy = BTGreaterStrategyNumber;
+
+ lower_or_arm_args = lappend(lower_or_arm_args,
+ make_partition_op_expr(key, j,
+ strategy,
+ keyCol,
+ (Expr *) lower_val));
+ }
+
+ if (need_next_upper_arm && upper_val)
+ {
+ uint16 strategy;
+
+ /*
+ * For the non-last columns of this arm, use the EQ operator.
+ * For the last finite-valued column, use LE.
+ */
+ if (j - i < current_or_arm)
+ strategy = BTEqualStrategyNumber;
+ else if (udatum_next && udatum_next->infinite)
+ strategy = BTLessEqualStrategyNumber;
+ else
+ strategy = BTLessStrategyNumber;
+
+ upper_or_arm_args = lappend(upper_or_arm_args,
+ make_partition_op_expr(key, j,
+ strategy,
+ keyCol,
+ (Expr *) upper_val));
+
+ }
+
+ /*
+ * Did we generate enough of OR's arguments? First arm considers
+ * the first of the remaining columns, second arm considers first
+ * two of the remaining columns, and so on.
+ */
+ ++j;
+ if (j - i > current_or_arm)
+ {
+ /*
+ * We need not emit the next arm if the new column that will
+ * be considered is unbounded.
+ */
+ need_next_lower_arm = ldatum_next && !ldatum_next->infinite;
+ need_next_upper_arm = udatum_next && !udatum_next->infinite;
+ break;
+ }
}
- /*
- * We can stop at this column, because we would not have checked the
- * next column when routing a given row into this partition.
- */
- break;
- }
+ if (lower_or_arm_args != NIL)
+ lower_or_arms = lappend(lower_or_arms,
+ list_length(lower_or_arm_args) > 1
+ ? makeBoolExpr(AND_EXPR, lower_or_arm_args, -1)
+ : linitial(lower_or_arm_args));
- return result;
-}
+ if (upper_or_arm_args != NIL)
+ upper_or_arms = lappend(upper_or_arms,
+ list_length(upper_or_arm_args) > 1
+ ? makeBoolExpr(AND_EXPR, upper_or_arm_args, -1)
+ : linitial(upper_or_arm_args));
-/*
- * get_partition_operator
- *
- * Return oid of the operator of given strategy for a given partition key
- * column.
- */
-static Oid
-get_partition_operator(PartitionKey key, int col, StrategyNumber strategy,
- bool *need_relabel)
-{
- Oid operoid;
+ /* If no work to do in the next iteration, break away. */
+ if (!need_next_lower_arm && !need_next_upper_arm)
+ break;
- /*
- * First check if there exists an operator of the given strategy, with
- * this column's type as both its lefttype and righttype, in the
- * partitioning operator family specified for the column.
- */
- operoid = get_opfamily_member(key->partopfamily[col],
- key->parttypid[col],
- key->parttypid[col],
- strategy);
+ ++current_or_arm;
+ }
/*
- * If one doesn't exist, we must resort to using an operator in the same
- * opreator family but with the operator class declared input type. It is
- * OK to do so, because the column's type is known to be binary-coercible
- * with the operator class input type (otherwise, the operator class in
- * question would not have been accepted as the partitioning operator
- * class). We must however inform the caller to wrap the non-Const
- * expression with a RelabelType node to denote the implicit coercion. It
- * ensures that the resulting expression structurally matches similarly
- * processed expressions within the optimizer.
+ * Generate the OR expressions for each of lower and upper bounds (if
+ * required), and append to the list of implicitly ANDed list of
+ * expressions.
*/
- if (!OidIsValid(operoid))
- {
- operoid = get_opfamily_member(key->partopfamily[col],
- key->partopcintype[col],
- key->partopcintype[col],
- strategy);
- *need_relabel = true;
- }
- else
- *need_relabel = false;
+ if (lower_or_arms != NIL)
+ result = lappend(result,
+ list_length(lower_or_arms) > 1
+ ? makeBoolExpr(OR_EXPR, lower_or_arms, -1)
+ : linitial(lower_or_arms));
+ if (upper_or_arms != NIL)
+ result = lappend(result,
+ list_length(upper_or_arms) > 1
+ ? makeBoolExpr(OR_EXPR, upper_or_arms, -1)
+ : linitial(upper_or_arms));
+
+ /* As noted above, caller expects the list to be non-empty. */
+ if (result == NULL)
+ result = list_make1(makeBoolConst(true, false));
- if (!OidIsValid(operoid))
- elog(ERROR, "could not find operator for partitioning");
-
- return operoid;
+ return result;
}
/*
projects / postgresql / commitdiff