From 97618036ff22138aefb3ba4e94c02ef8f1fdcdde Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 22 Nov 2019 09:23:34 -0500 Subject: [PATCH v10 1/3] tableam: Allow choice of toast AM. Previously, the toast table had to be implemented by the same AM that was used for the main table, which was bad, because the detoasting code won't work with anything but heap. This commit doesn't fix the latter problem, though I plan to do that in a later commit, but it does let you choose what AM you'd like to use, so that a table AM can at least choose heap and get something that works. Patch by me, reviewed by Andres Freund. Discussion: http://postgr.es/m/CA+TgmoZv-=2iWM4jcw5ZhJeL18HF96+W1yJeYrnGMYdkFFnEpQ@mail.gmail.com --- src/backend/access/heap/heapam_handler.c | 10 ++++++++++ src/backend/catalog/toasting.c | 2 +- src/include/access/tableam.h | 17 +++++++++++++++++ 3 files changed, 28 insertions(+), 1 deletion(-) diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c index 92073fec54..1d053e74e6 100644 --- a/src/backend/access/heap/heapam_handler.c +++ b/src/backend/access/heap/heapam_handler.c @@ -2037,6 +2037,15 @@ heapam_relation_needs_toast_table(Relation rel) return (tuple_length > TOAST_TUPLE_THRESHOLD); } +/* + * TOAST tables for heap relations are just heap relations. + */ +static Oid +heapam_relation_toast_am(Relation rel) +{ + return rel->rd_rel->relam; +} + /* ------------------------------------------------------------------------ * Planner related callbacks for the heap AM @@ -2535,6 +2544,7 @@ static const TableAmRoutine heapam_methods = { .relation_size = table_block_relation_size, .relation_needs_toast_table = heapam_relation_needs_toast_table, + .relation_toast_am = heapam_relation_toast_am, .relation_estimate_size = heapam_estimate_rel_size, diff --git a/src/backend/catalog/toasting.c b/src/backend/catalog/toasting.c index de6282a667..f082463bf6 100644 --- a/src/backend/catalog/toasting.c +++ b/src/backend/catalog/toasting.c @@ -258,7 +258,7 @@ create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid, toast_typid, InvalidOid, rel->rd_rel->relowner, - rel->rd_rel->relam, + table_relation_toast_am(rel), tupdesc, NIL, RELKIND_TOASTVALUE, diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h index 64022917e2..7ac9bb6d65 100644 --- a/src/include/access/tableam.h +++ b/src/include/access/tableam.h @@ -581,6 +581,13 @@ typedef struct TableAmRoutine */ bool (*relation_needs_toast_table) (Relation rel); + /* + * This callback should return the OID of the table AM that implements + * TOAST tables for this AM. If the relation_needs_toast_table callback + * always returns false, this callback is not required. + */ + Oid (*relation_toast_am) (Relation rel); + /* ------------------------------------------------------------------------ * Planner related functions. @@ -1603,6 +1610,16 @@ table_relation_needs_toast_table(Relation rel) return rel->rd_tableam->relation_needs_toast_table(rel); } +/* + * Return the OID of the AM that should be used to implement the TOAST table + * for this relation. + */ +static inline Oid +table_relation_toast_am(Relation rel) +{ + return rel->rd_tableam->relation_toast_am(rel); +} + /* ---------------------------------------------------------------------------- * Planner related functionality -- 2.17.2 (Apple Git-113)