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ProvSQL C/C++ API
Adding support for provenance and uncertainty management to PostgreSQL databases
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ProvSQL C/C++ API
Adding support for provenance and uncertainty management to PostgreSQL databases
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Per-atom rewrite metadata discovered by the hierarchy detector. More...
Public Attributes | |
| Index | rtindex |
| List * | proj_slots |
| List * | pushed_quals |
| int | group_id |
-1 for atoms wrapped directly at the outer (one SELECT DISTINCT subquery per atom); >= 0 indexes into the rewrite's groups list and means the atom is a member of an inner sub-Query built around a partial-coverage shared class. | |
| Index | outer_rtindex |
| Assigned by the rewriter: this atom's slot in the rebuilt outer rtable. Grouped atoms all share their group's outer_rtindex. | |
| Index | inner_rtindex |
| Assigned by the rewriter for grouped atoms only: position inside the inner sub-Query's rtable (1-based). 0 for outer-wrap atoms. | |
| AttrNumber | root_anchor_attno |
For grouped atoms: base attno of the root-class binding column inside this atom. Used by the outer Var remap to recognise root-class references that should resolve to the inner sub-Query's single output column. | |
| bool | is_constant_pinned |
Reserved for future constant-selection follow-up work; currently never set (constant-pinned atoms are routed through the multi-component path before this struct is built, so each atom in rewrite_hierarchical_cq is unconditionally a regular hierarchical-component atom). | |
Per-atom rewrite metadata discovered by the hierarchy detector.
rtindex is the 1-based index into q->rtable that matches Var.varno. proj_slots is the ordered list of safe_proj_slot * to project out of this atom's inner SELECT DISTINCT. The root-class slot is always first. Additional shared classes touching this atom (column pushdown) follow in ascending class-repr order.
pushed_quals is the list of WHERE conjuncts that reference only this atom (single-atom Vars only) and were extracted from the outer query before the hierarchy analysis ran. They are AND-injected into the inner subquery's WHERE after a varno remap from rtindex to 1, so the atom-local predicates evaluate before the DISTINCT and the offending single-atom Vars never reach the outer scope.
Definition at line 291 of file safe_query.c.
| int safe_rewrite_atom::group_id |
-1 for atoms wrapped directly at the outer (one SELECT DISTINCT subquery per atom); >= 0 indexes into the rewrite's groups list and means the atom is a member of an inner sub-Query built around a partial-coverage shared class.
Definition at line 295 of file safe_query.c.
| Index safe_rewrite_atom::inner_rtindex |
Assigned by the rewriter for grouped atoms only: position inside the inner sub-Query's rtable (1-based). 0 for outer-wrap atoms.
Definition at line 297 of file safe_query.c.
| bool safe_rewrite_atom::is_constant_pinned |
Reserved for future constant-selection follow-up work; currently never set (constant-pinned atoms are routed through the multi-component path before this struct is built, so each atom in rewrite_hierarchical_cq is unconditionally a regular hierarchical-component atom).
Definition at line 299 of file safe_query.c.
| Index safe_rewrite_atom::outer_rtindex |
Assigned by the rewriter: this atom's slot in the rebuilt outer rtable. Grouped atoms all share their group's outer_rtindex.
Definition at line 296 of file safe_query.c.
| List* safe_rewrite_atom::proj_slots |
Definition at line 293 of file safe_query.c.
| List* safe_rewrite_atom::pushed_quals |
Definition at line 294 of file safe_query.c.
| AttrNumber safe_rewrite_atom::root_anchor_attno |
For grouped atoms: base attno of the root-class binding column inside this atom. Used by the outer Var remap to recognise root-class references that should resolve to the inner sub-Query's single output column.
Definition at line 298 of file safe_query.c.
| Index safe_rewrite_atom::rtindex |
Definition at line 292 of file safe_query.c.