This will be useful for array and composite types that may have to
support elements that may not support binary encoding.
It also is slightly more convenient for text-ish types to have a default
format of text.
PlanScan used to require the exact same value be used every time. While
this was great for performance, on further consideration I think it is
too much of a potential foot-gun.
This moves back in the other direction. A plan tolerates a change in
destination. It even detects a change in destination type and falls
back to a new plan.
Perfectly matched hot scan paths (e.g. PG int4 to Go int32) are still
much faster than they were before this set of optimizations. The first
scan of a destination that uses a decoder is faster due to not
allocating. It's a little bit slower on subsequent runs than before
this set of optimizations. But it is preferable to optimize for the
most common scan targets (e.g. *int32, *int64, *string) over generic
decoder destinations.
In addition this fees pgx.connRows.Scan from having to check that
the destination is unchanged.
This allows registering a mapping of a Go type to a PostgreSQL type
name. If the OID of a value to be encoded or decoded is unknown, this
additional mapping will be used to determine a suitable data type.
It was a mistake to use it in other contexts. This made interop
difficult between pacakges that depended on pgtype such as pgx and
packages that did not like pgconn and pgproto3. In particular this was
awkward for prepared statements.
Because pgx depends on pgtype and the tests for pgtype depend on pgx
this change will require a couple back and forth commits to get the
go.mod dependecies correct.
Because reading a record type requires the decoder to be able to look up oid
to type mapping and types such as hstore have types that are not fixed between
different PostgreSQL servers it was necessary to restructure the pgtype system
so all encoders and decodes take a *ConnInfo that includes oid/name/type
information.
Though this doesn't follow Go naming conventions exactly it makes names more
consistent with PostgreSQL and it is easier to read. For example, TIDOID becomes
TidOid. In addition this is one less breaking change in the move to V3.
To aid in composability, these methods no longer write their own length. This
is especially useful for text formatted arrays and may be useful for future
database/sql compatibility. It also makes the code a little simpler as the
types no longer have to compute their own size.
Along with this, these methods cannot encode NULL. They now return a boolean
if they are NULL. This also benefits text array encoding as numeric arrays
require NULL to be exactly `NULL` while string arrays require NULL to be
`"NULL"`.
Squashed commit of the following:
commit c19454582b
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Mar 3 15:24:47 2017 -0600
Add AssignTo to pgtype.Timestamptz
Also handle infinity for pgtype.Date
commit 7329933610
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Mar 3 15:12:18 2017 -0600
Implement AssignTo for most pgtypes
commit cc3d1e4af8
Author: Jack Christensen <jack@jackchristensen.com>
Date: Thu Mar 2 21:19:07 2017 -0600
Use pgtype.Int2Array in pgx
commit 36da5cc217
Author: Jack Christensen <jack@jackchristensen.com>
Date: Tue Feb 28 21:45:33 2017 -0600
Add text array transcoding
commit 1b0f18d99f
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 27 19:28:55 2017 -0600
Add ParseUntypedTextArray
commit 0f50ce3e83
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 27 18:54:20 2017 -0600
wip
commit d934f27362
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sun Feb 26 17:14:32 2017 -0600
WIP - beginning text format array parsing
commit 7276ad33ce
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 22:50:11 2017 -0600
Beginning binary arrays
commit 917faa5a31
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 19:36:35 2017 -0600
Fix incomplete tests
commit de8c140cfb
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 19:32:22 2017 -0600
Add timestamptz null and infinity
commit 7d9f954de4
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 18:19:38 2017 -0600
Add infinity to pgtype.Date
commit 7bf783ae20
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 17:19:55 2017 -0600
Add Status to pgtype.Date
commit 984500455c
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 16:54:01 2017 -0600
Add status to Int4 and Int8
commit 6fe76fcfc2
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 16:40:27 2017 -0600
Extract testSuccessfulTranscode
commit 001647c1da
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 16:15:51 2017 -0600
Add Status to pgtype.Int2
commit 720451f06d
Author: Jack Christensen <jack@jackchristensen.com>
Date: Sat Feb 25 15:56:44 2017 -0600
Add status to pgtype.Bool
commit 325f700b6e
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 17:28:15 2017 -0600
Add date to conversion system
commit 4a9343e45d
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 16:28:35 2017 -0600
Add bool to oid based encoding
commit d984fcafab
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 16:15:38 2017 -0600
Add pgtype interfaces
commit 0f93bfc2de
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 14:48:34 2017 -0600
Begin introduction of Convert
commit e5707023ca
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 14:10:56 2017 -0600
Move bool to pgtype
commit bb764d2129
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 13:45:05 2017 -0600
Add Int2 test
commit 08c49437f4
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 13:44:09 2017 -0600
Add Int4 test
commit 1672295222
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 24 08:56:59 2017 -0600
Add int8 tests
commit 83a5447cd2
Author: Jack Christensen <jack@jackchristensen.com>
Date: Wed Feb 22 18:08:05 2017 -0600
wip
commit 0ca0ee7206
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 18:56:52 2017 -0600
wip
commit d2c2baf4ea
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 18:46:10 2017 -0600
wip
commit f78371da00
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 17:43:39 2017 -0600
wip
commit 3366699bea
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 14:07:47 2017 -0600
wip
commit 66b79e9408
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 13:35:37 2017 -0600
Extract pgio
commit 8b07d97d13
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 13:20:00 2017 -0600
wip
commit 62f1adb342
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 12:08:46 2017 -0600
wip
commit a712d25469
Author: Jack Christensen <jack@jackchristensen.com>
Date: Mon Feb 20 09:30:52 2017 -0600
wip
commit 4faf97cc58
Author: Jack Christensen <jack@jackchristensen.com>
Date: Fri Feb 17 22:20:18 2017 -0600
wip