This commit adds the SQLiteConn.FileControlInt() method which calls the
underlying sqlite3_file_control() function with an int argument. This can
be used for low-level operations on SQLite databases such as persisting
the WAL file after database close.
Selecting only some tests with go test -run=... does not work, because
some of the tests are executed using testing.RunTests(). That function
is documented as "an internal function". This changes TestSuite to use
the testing subtests feature instead.
This has a behaviour change: the benchmarks now need to be
selected at the command line with the standard go test -bench=.
flag. This will also set up the test database twice when running
benchmarks, rather than once.
* sqlite3_type update
The main reason for this change is that the original reflected values are nil. I found that there was no good mapping when dealing with the code here
* Update sqlite3_type.go
Update 'ColumnTypeScanType' method,
Different types of mapping values
* Restore copyright
* Update go.mod
* Update go.mod
The busy_timeout pragma was added in sqlite 3.7.15 as an alternative
to calling sqlite3_busy_timeout directly:
https://sqlite.org/pragma.html#pragma_busy_timeout
While there's no functional change here, using the pragma does align
setting busy_timeout with other settings and removes the special case
for calling sqlite3_busy_timeout directly.
This can be used like in the test; I wrote a little wrapper around
sql.DB which uses this, and allows concurrent reads but just one single
write. This is perhaps a better generic "table locked"-solution than
setting the connections to 1 and/or cache=shared (although even better
would be to design your app in such a way that this doesn't happpen in
the first place, but even then a little seat belt isn't a bad thing).
The parsing adds about 0.1ms to 0.2ms of overhead in the wrapper, which
isn't too bad (and it caches the results, so only needs to do this
once).
At any rate, I can't really access functions from sqlite3-binding.c from
my application, so expose it via SQLiteStmt.
Add a shortcut for PRAGMA cache_size; this is a pretty useful setting:
the default of -2000 (2M) is not especially high, and a lot of people
will probably want to increase this.
For example, while running a bunch of fairy expensive queries in
parallel:
With SetMaxOpenConns(1):
-2000: 5762ms
-20000: 4714ms
With SetMaxOpenConns(20):
-2000: 3067ms
-20000: 2532ms
Which isn't a bad performance boost for changing a single number.
This option was enabled by default in sqlite3 on 2014-07-03.
This setting does nothing. It can now be disabled with
SQLITE_DISABLE_FTS3_UNICODE. See the upstream commit:
https://sqlite.org/src/info/0cc0230ae9cfc976
I think this change was imported into this project with commit
ee9da4840d on 2015-06-12.
This "disables the use of compiler-specific built-in functions such
as __builtin_bswap32()" (from the SQLite docs) so this change might
produce slightly better code. My primary motivation, however, is that
the "default" configuration for SQLite, which is widely tested, does
not set this preprocessor macro.
From looking at Github issues, it appears this was added to avoid a
build error on Mac OS X 10.11, in 2017:
https://github.com/mattn/go-sqlite3/issues/386
There have been a number of changes to sqlite3 since we tried this
last. I think it would be worth trying to remove this setting again.
I found a machine running Mac OS X 10.11.6. It was able to build and
run the tests in this package with this change.
Mac OS X 10.11 is has not been supported by Apple since 2018
(currently Apple is releasing updates for Mac OS 10.13 and newer; 11
is the current release). However, Go 1.14 is supported, and it
requires Mac OS X 10.11 or newer: https://golang.org/doc/go1.14
Go 1.15 only supports Mac OS 10.12 and newer:
https://golang.org/doc/go1.15
Yasuhiro Matsumoto