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Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE.

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The newly added ON CONFLICT clause allows to specify an alternative to
raising a unique or exclusion constraint violation error when inserting.
ON CONFLICT refers to constraints that can either be specified using a
inference clause (by specifying the columns of a unique constraint) or
by naming a unique or exclusion constraint.  DO NOTHING avoids the
constraint violation, without touching the pre-existing row.  DO UPDATE
SET ... [WHERE ...] updates the pre-existing tuple, and has access to
both the tuple proposed for insertion and the existing tuple; the
optional WHERE clause can be used to prevent an update from being
executed.  The UPDATE SET and WHERE clauses have access to the tuple
proposed for insertion using the "magic" EXCLUDED alias, and to the
pre-existing tuple using the table name or its alias.

This feature is often referred to as upsert.

This is implemented using a new infrastructure called "speculative
insertion". It is an optimistic variant of regular insertion that first
does a pre-check for existing tuples and then attempts an insert.  If a
violating tuple was inserted concurrently, the speculatively inserted
tuple is deleted and a new attempt is made.  If the pre-check finds a
matching tuple the alternative DO NOTHING or DO UPDATE action is taken.
If the insertion succeeds without detecting a conflict, the tuple is
deemed inserted.

To handle the possible ambiguity between the excluded alias and a table
named excluded, and for convenience with long relation names, INSERT
INTO now can alias its target table.

Bumps catversion as stored rules change.

Author: Peter Geoghegan, with significant contributions from Heikki
    Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes.
Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs,
    Dean Rasheed, Stephen Frost and many others.
This commit is contained in:
Andres Freund
2015-05-08 05:31:36 +02:00
parent 2c8f4836db
commit 168d5805e4
122 changed files with 6111 additions and 440 deletions
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54
src/include/access/heapam_xlog.h
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@ -34,7 +34,7 @@
#define XLOG_HEAP_UPDATE 0x20
/* 0x030 is free, was XLOG_HEAP_MOVE */
#define XLOG_HEAP_HOT_UPDATE 0x40
/* 0x050 is free, was XLOG_HEAP_NEWPAGE */
#define XLOG_HEAP_CONFIRM 0x50
#define XLOG_HEAP_LOCK 0x60
#define XLOG_HEAP_INPLACE 0x70
@ -60,23 +60,43 @@
#define XLOG_HEAP2_NEW_CID 0x70
/*
* xl_heap_* ->flag values, 8 bits are available.
* xl_heap_insert/xl_heap_multi_insert flag values, 8 bits are available.
*/
/* PD_ALL_VISIBLE was cleared */
#define XLOG_HEAP_ALL_VISIBLE_CLEARED (1<<0)
#define XLH_INSERT_ALL_VISIBLE_CLEARED (1<<0)
#define XLH_INSERT_LAST_IN_MULTI (1<<1)
#define XLH_INSERT_IS_SPECULATIVE (1<<2)
#define XLH_INSERT_CONTAINS_NEW_TUPLE (1<<3)
/*
* xl_heap_update flag values, 8 bits are available.
*/
/* PD_ALL_VISIBLE was cleared */
#define XLH_UPDATE_OLD_ALL_VISIBLE_CLEARED (1<<0)
/* PD_ALL_VISIBLE was cleared in the 2nd page */
#define XLOG_HEAP_NEW_ALL_VISIBLE_CLEARED (1<<1)
#define XLOG_HEAP_CONTAINS_OLD_TUPLE (1<<2)
#define XLOG_HEAP_CONTAINS_OLD_KEY (1<<3)
#define XLOG_HEAP_CONTAINS_NEW_TUPLE (1<<4)
#define XLOG_HEAP_PREFIX_FROM_OLD (1<<5)
#define XLOG_HEAP_SUFFIX_FROM_OLD (1<<6)
/* last xl_heap_multi_insert record for one heap_multi_insert() call */
#define XLOG_HEAP_LAST_MULTI_INSERT (1<<7)
#define XLH_UPDATE_NEW_ALL_VISIBLE_CLEARED (1<<1)
#define XLH_UPDATE_CONTAINS_OLD_TUPLE (1<<2)
#define XLH_UPDATE_CONTAINS_OLD_KEY (1<<3)
#define XLH_UPDATE_CONTAINS_NEW_TUPLE (1<<4)
#define XLH_UPDATE_PREFIX_FROM_OLD (1<<5)
#define XLH_UPDATE_SUFFIX_FROM_OLD (1<<6)
/* convenience macro for checking whether any form of old tuple was logged */
#define XLOG_HEAP_CONTAINS_OLD \
(XLOG_HEAP_CONTAINS_OLD_TUPLE | XLOG_HEAP_CONTAINS_OLD_KEY)
#define XLH_UPDATE_CONTAINS_OLD \
(XLH_UPDATE_CONTAINS_OLD_TUPLE | XLH_UPDATE_CONTAINS_OLD_KEY)
/*
* xl_heap_delete flag values, 8 bits are available.
*/
/* PD_ALL_VISIBLE was cleared */
#define XLH_DELETE_ALL_VISIBLE_CLEARED (1<<0)
#define XLH_DELETE_CONTAINS_OLD_TUPLE (1<<1)
#define XLH_DELETE_CONTAINS_OLD_KEY (1<<2)
#define XLH_DELETE_IS_SUPER (1<<3)
/* convenience macro for checking whether any form of old tuple was logged */
#define XLH_DELETE_CONTAINS_OLD \
(XLH_DELETE_CONTAINS_OLD_TUPLE | XLH_DELETE_CONTAINS_OLD_KEY)
/* This is what we need to know about delete */
typedef struct xl_heap_delete
@ -243,6 +263,14 @@ typedef struct xl_heap_lock_updated
#define SizeOfHeapLockUpdated (offsetof(xl_heap_lock_updated, infobits_set) + sizeof(uint8))
/* This is what we need to know about confirmation of speculative insertion */
typedef struct xl_heap_confirm
{
OffsetNumber offnum; /* confirmed tuple's offset on page */
} xl_heap_confirm;
#define SizeOfHeapConfirm (offsetof(xl_heap_confirm, offnum) + sizeof(OffsetNumber))
/* This is what we need to know about in-place update */
typedef struct xl_heap_inplace
{