# 4.11.0 (March 25, 2021)

* Add BeforeConnect callback to pgxpool.Config (Robert Froehlich)
* Add Ping method to pgxpool.Conn (davidsbond)
* Added a kitlog level log adapter (Fabrice Aneche)
* Make ScanArgError public to allow identification of offending column (Pau Sanchez)
* Add *pgxpool.AcquireFunc
* Add BeginFunc and BeginTxFunc
* Add prefer_simple_protocol to connection string
* Add logging on CopyFrom (Patrick Hemmer)
* Add comment support when sanitizing SQL queries (Rusakow Andrew)
* Do not panic on double close of pgxpool.Pool (Matt Schultz)
* Avoid panic on SendBatch on closed Tx (Matt Schultz)
* Update pgconn to v1.8.1
* Update pgtype to v1.7.0

# 4.10.1 (December 19, 2020)

* Fix panic on Query error with nil stmtcache.

# 4.10.0 (December 3, 2020)

* Add CopyFromSlice to simplify CopyFrom usage (Egon Elbre)
* Remove broken prepared statements from stmtcache (Ethan Pailes)
* stdlib: consider any Ping error as fatal
* Update puddle to v1.1.3 - this fixes an issue where concurrent Acquires can hang when a connection cannot be established
* Update pgtype to v1.6.2

# 4.9.2 (November 3, 2020)

The underlying library updates fix an issue where appending to a scanned slice could corrupt other data.

* Update pgconn to v1.7.2
* Update pgproto3 to v2.0.6

# 4.9.1 (October 31, 2020)

* Update pgconn to v1.7.1
* Update pgtype to v1.6.1
* Fix SendBatch of all prepared statements with statement cache disabled

# 4.9.0 (September 26, 2020)

* pgxpool now waits for connection cleanup to finish before making room in pool for another connection. This prevents temporarily exceeding max pool size.
* Fix when scanning a column to nil to skip it on the first row but scanning it to a real value on a subsequent row.
* Fix prefer simple protocol with prepared statements. (Jinzhu)
* Fix FieldDescriptions not being available on Rows before calling Next the first time.
* Various minor fixes in updated versions of pgconn, pgtype, and puddle.

# 4.8.1 (July 29, 2020)

* Update pgconn to v1.6.4
    * Fix deadlock on error after CommandComplete but before ReadyForQuery
    * Fix panic on parsing DSN with trailing '='

# 4.8.0 (July 22, 2020)

* All argument types supported by native pgx should now also work through database/sql
* Update pgconn to v1.6.3
* Update pgtype to v1.4.2

# 4.7.2 (July 14, 2020)

* Improve performance of Columns() (zikaeroh)
* Fix fatal Commit() failure not being considered fatal
* Update pgconn to v1.6.2
* Update pgtype to v1.4.1

# 4.7.1 (June 29, 2020)

* Fix stdlib decoding error with certain order and combination of fields

# 4.7.0 (June 27, 2020)

* Update pgtype to v1.4.0
* Update pgconn to v1.6.1
* Update puddle to v1.1.1
* Fix context propagation with Tx commit and Rollback (georgysavva)
* Add lazy connect option to pgxpool (georgysavva)
* Fix connection leak if pgxpool.BeginTx() fail (Jean-Baptiste Bronisz)
* Add native Go slice support for strings and numbers to simple protocol
* stdlib add default timeouts for Conn.Close() and Stmt.Close() (georgysavva)
* Assorted performance improvements especially with large result sets
* Fix close pool on not lazy connect failure (Yegor Myskin)
* Add Config copy (georgysavva)
* Support SendBatch with Simple Protocol (Jordan Lewis)
* Better error logging on rows close (Igor V. Kozinov)
* Expose stdlib.Conn.Conn() to enable database/sql.Conn.Raw()
* Improve unknown type support for database/sql
* Fix transaction commit failure closing connection

# 4.6.0 (March 30, 2020)

* stdlib: Bail early if preloading rows.Next() results in rows.Err() (Bas van Beek)
* Sanitize time to microsecond accuracy (Andrew Nicoll)
* Update pgtype to v1.3.0
* Update pgconn to v1.5.0
    * Update golang.org/x/crypto for security fix
    * Implement "verify-ca" SSL mode

# 4.5.0 (March 7, 2020)

* Update to pgconn v1.4.0
    * Fixes QueryRow with empty SQL
    * Adds PostgreSQL service file support
* Add Len() to *pgx.Batch (WGH)
* Better logging for individual batch items (Ben Bader)

# 4.4.1 (February 14, 2020)

* Update pgconn to v1.3.2 - better default read buffer size
* Fix race in CopyFrom

# 4.4.0 (February 5, 2020)

* Update puddle to v1.1.0 - fixes possible deadlock when acquire is cancelled
* Update pgconn to v1.3.1 - fixes CopyFrom deadlock when multiple NoticeResponse received during copy
* Update pgtype to v1.2.0
* Add MaxConnIdleTime to pgxpool (Patrick Ellul)
* Add MinConns to pgxpool (Patrick Ellul)
* Fix: stdlib.ReleaseConn closes connections left in invalid state

# 4.3.0 (January 23, 2020)

* Fix Rows.Values panic when unable to decode
* Add Rows.Values support for unknown types
* Add DriverContext support for stdlib (Alex Gaynor)
* Update pgproto3 to v2.0.1 to never return an io.EOF as it would be misinterpreted by database/sql. Instead return io.UnexpectedEOF.

# 4.2.1 (January 13, 2020)

* Update pgconn to v1.2.1 (fixes context cancellation data race introduced in v1.2.0))

# 4.2.0 (January 11, 2020)

* Update pgconn to v1.2.0.
* Update pgtype to v1.1.0.
* Return error instead of panic when wrong number of arguments passed to Exec. (malstoun)
* Fix large objects functionality when PreferSimpleProtocol = true.
* Restore GetDefaultDriver which existed in v3. (Johan Brandhorst)
* Add RegisterConnConfig to stdlib which replaces the removed RegisterDriverConfig from v3.

# 4.1.2 (October 22, 2019)

* Fix dbSavepoint.Begin recursive self call
* Upgrade pgtype to v1.0.2 - fix scan pointer to pointer

# 4.1.1 (October 21, 2019)

* Fix pgxpool Rows.CommandTag() infinite loop / typo

# 4.1.0 (October 12, 2019)

## Potentially Breaking Changes

Technically, two changes are breaking changes, but in practice these are extremely unlikely to break existing code.

* Conn.Begin and Conn.BeginTx return a Tx interface instead of the internal dbTx struct. This is necessary for the Conn.Begin method to signature as other methods that begin a transaction.
* Add Conn() to Tx interface. This is necessary to allow code using a Tx to access the *Conn (and pgconn.PgConn) on which the Tx is executing.

## Fixes

* Releasing a busy connection closes the connection instead of returning an unusable connection to the pool
* Do not mutate config.Config.OnNotification in connect

# 4.0.1 (September 19, 2019)

* Fix statement cache cleanup.
* Corrected daterange OID.
* Fix Tx when committing or rolling back multiple times in certain cases.
* Improve documentation.

# 4.0.0 (September 14, 2019)

v4 is a major release with many significant changes some of which are breaking changes. The most significant are
included below.

* Simplified establishing a connection with a connection string.
* All potentially blocking operations now require a context.Context. The non-context aware functions have been removed.
* OIDs are hard-coded for known types. This saves the query on connection.
* Context cancellations while network activity is in progress is now always fatal. Previously, it was sometimes recoverable. This led to increased complexity in pgx itself and in application code.
* Go modules are required.
* Errors are now implemented in the Go 1.13 style.
* `Rows` and `Tx` are now interfaces.
* The connection pool as been decoupled from pgx and is now a separate, included package (github.com/jackc/pgx/v4/pgxpool).
* pgtype has been spun off to a separate package (github.com/jackc/pgtype).
* pgproto3 has been spun off to a separate package (github.com/jackc/pgproto3/v2).
* Logical replication support has been spun off to a separate package (github.com/jackc/pglogrepl).
* Lower level PostgreSQL functionality is now implemented in a separate package (github.com/jackc/pgconn).
* Tests are now configured with environment variables.
* Conn has an automatic statement cache by default.
* Batch interface has been simplified.
* QueryArgs has been removed.
