orclauses.h File Reference

#include "nodes/pathnodes.h"

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Functions
void	extract_restriction_or_clauses (PlannerInfo *root)

Function Documentation

extract_restriction_or_clauses()

void extract_restriction_or_clauses

(

PlannerInfo *

root

)

Definition at line 75 of file orclauses.c.

{
    Index       rti;
 
    /* Examine each baserel for potential join OR clauses */
    for (rti = 1; rti < root->simple_rel_array_size; rti++)
    {
        RelOptInfo *rel = root->simple_rel_array[rti];
        ListCell   *lc;
 
        /* there may be empty slots corresponding to non-baserel RTEs */
        if (rel == NULL)
            continue;
 
        Assert(rel->relid == rti);  /* sanity check on array */
 
        /* ignore RTEs that are "other rels" */
        if (rel->reloptkind != RELOPT_BASEREL)
            continue;
 
        /*
         * Find potentially interesting OR joinclauses.  We can use any
         * joinclause that is considered safe to move to this rel by the
         * parameterized-path machinery, even though what we are going to do
         * with it is not exactly a parameterized path.
         */
        foreach(lc, rel->joininfo)
        {
            RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
 
            if (restriction_is_or_clause(rinfo) &&
                join_clause_is_movable_to(rinfo, rel))
            {
                /* Try to extract a qual for this rel only */
                Expr       *orclause = extract_or_clause(rinfo, rel);
 
                /*
                 * If successful, decide whether we want to use the clause,
                 * and insert it into the rel's restrictinfo list if so.
                 */
                if (orclause)
                    consider_new_or_clause(root, rel, orclause, rinfo);
            }
        }
    }
}

References Assert(), consider_new_or_clause(), extract_or_clause(), join_clause_is_movable_to(), RelOptInfo::joininfo, lfirst, RelOptInfo::relid, RELOPT_BASEREL, RelOptInfo::reloptkind, restriction_is_or_clause(), and root.

Referenced by query_planner().