If the default_query_exec_mode is unknown, the returned error
previously was:
invalid default_query_exec_mode: <nil>
This changes it to return the argument. Add a test that unknown modes
fail to parse and include this string.
Previously, items were never removed from the preparedStatements map.
This means workloads that send a large number of unique queries could
run out of memory. Delete items from the map when sending the
deallocate command to Postgres. Add a test to verify this works.
Fixes https://github.com/jackc/pgx/issues/1456
Table types have system / hidden columns like tableoid, cmax, xmax, etc.
These are not included when sending or receiving composite types.
https://github.com/jackc/pgx/issues/1576
CopyFrom had to create a prepared statement to get the OIDs of the data
types that were going to be copied into the table. Every COPY operation
required an extra round trips to retrieve the type information. There
was no way to customize this behavior.
By leveraging the QueryExecMode feature, like in `Conn.Query`, users can
specify if they want to cache the prepared statements, execute
them on every request (like the old behavior), or bypass the prepared
statement relying on the pgtype.Map to get the type information.
The `QueryExecMode` behave exactly like in `Conn.Query` in the way the
data type OIDs are fetched, meaning that:
- `QueryExecModeCacheStatement`: caches the statement.
- `QueryExecModeCacheDescribe`: caches the statement and assumes they do
not change.
- `QueryExecModeDescribeExec`: gets the statement description on every
execution. This is like to the old behavior of `CopyFrom`.
- `QueryExecModeExec` and `QueryExecModeSimpleProtocol`: maintain the
same behavior as before, which is the same as `QueryExecModeDescribeExec`.
It will keep getting the statement description on every execution
The `QueryExecMode` can only be set via
`ConnConfig.DefaultQueryExecMode`, unlike `Conn.Query` there's no
support for specifying the `QueryExecMode` via optional arguments
in the function signature.
Previously, a batch with 10 unique parameterized statements executed
100 times would entail 11 network round trips. 1 for each prepare /
describe and 1 for executing them all. Now pipeline mode is used to
prepare / describe all statements in a single network round trip. So it
would only take 2 round trips.
Added ValueRoundTripTest to pgxtest
Removed pgtype/testutil
pgtype tests now run with all (applicable) query modes. This gives
better coverage than before and revealed several bugs which are also
fixed in this commit.
