diff options
Diffstat (limited to 'doc/src/sgml/custom-scan.sgml')
| -rw-r--r-- | doc/src/sgml/custom-scan.sgml | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/doc/src/sgml/custom-scan.sgml b/doc/src/sgml/custom-scan.sgml index 62a8a3305bb..dc327b11b21 100644 --- a/doc/src/sgml/custom-scan.sgml +++ b/doc/src/sgml/custom-scan.sgml @@ -60,6 +60,7 @@ typedef struct CustomPath { Path path; uint32 flags; + List *custom_paths; List *custom_private; const CustomPathMethods *methods; } CustomPath; @@ -73,6 +74,9 @@ typedef struct CustomPath <literal>CUSTOMPATH_SUPPORT_BACKWARD_SCAN</> if the custom path can support a backward scan and <literal>CUSTOMPATH_SUPPORT_MARK_RESTORE</> if it can support mark and restore. Both capabilities are optional. + An optional <structfield>custom_paths</> is a list of <structname>Path</> + nodes used by this custom-path node; these will be transformed into + <structname>Plan</> nodes by planner. <structfield>custom_private</> can be used to store the custom path's private data. Private data should be stored in a form that can be handled by <literal>nodeToString</>, so that debugging routines that attempt to @@ -112,7 +116,8 @@ Plan *(*PlanCustomPath) (PlannerInfo *root, RelOptInfo *rel, CustomPath *best_path, List *tlist, - List *clauses); + List *clauses, + List *custom_plans); </programlisting> Convert a custom path to a finished plan. The return value will generally be a <literal>CustomScan</> object, which the callback must allocate and @@ -145,6 +150,7 @@ typedef struct CustomScan { Scan scan; uint32 flags; + List *custom_plans; List *custom_exprs; List *custom_private; List *custom_scan_tlist; @@ -159,6 +165,8 @@ typedef struct CustomScan estimated costs, target lists, qualifications, and so on. <structfield>flags</> is a bitmask with the same meaning as in <structname>CustomPath</>. + <structfield>custom_plans</> can be used to store child + <structname>Plan</> nodes. <structfield>custom_exprs</> should be used to store expression trees that will need to be fixed up by <filename>setrefs.c</> and <filename>subselect.c</>, while |