isabella232 / stmtcacher

Prepared statement caching for go

stmtcacher

Prepared statement caching for go's sql.DB.

CachingWrapper

Wrapper around DB with additional functions that explicitly reuse cached prepared statements. All sql.DB query functions are wrapped and available with the suffix "Prepared", e.g. QueryPrepared, ExecPrepared

db, err := sql.Open("sqlite3", ":memory:")
if err != nil {
	// ...
}

wrapper := stmtcacher.NewCachingWrapper(db)

query := "SELECT * FROM table where id = ?"

// By default, sql.DB will perform 3 statements and roundtrips
db.Query(query, "foo")
// PREPARE 'SELECT * FROM table where name = ?'
// EXECUTE stmt1, "foo"
// CLOSE stmt1
db.Query(query, "bar")
// PREPARE 'SELECT * FROM table where name = ?'
// EXECUTE stmt2, "bar"
// CLOSE

// With stmtcacher, they're cached
wrapper.QueryPrepared(query, "foo")
// PREPARE 'SELECT * FROM table where name = ?'
// EXECUTE stmt1, "foo"
wrapper.QueryPrepared(query, "bar")
// EXECUTE stmt1, "bar"
wrapper.QueryPrepared(query, "baz")
// EXECUTE stmt1, "baz"

// sql.DB is embedded and available to
// easily opt-in or out of the behavior
wrapper.Query(query, "bar")
// PREPARE 'SELECT * FROM table where name = ?'
// EXECUTE stmt2, "bar"
// CLOSE

CachingProxy

Caching proxy and wrapper around sql.DB. Exec, Query, QueryRow, ExecContext, QueryContext, and QueryRowContext are each wrapped to cache and reuse prepared statements

db, err := sql.Open("sqlite3", ":memory:")
if err != nil {
	// ...
}

proxy := stmtcacher.NewCachingProxy(db)

query := "SELECT * FROM table where name = ?"

// By default, sql.DB will perform 3 statements and roundtrips
db.Query(query, "foo")
// PREPARE 'SELECT * FROM table where name = ?'
// EXECUTE stmt1, "foo"
// CLOSE stmt1
db.Query(query, "bar")
// PREPARE 'SELECT * FROM table where name = ?'
// EXECUTE stmt2, "bar"
// CLOSE

// With stmtcacher, they're cached
proxy.Query(query, "foo")
// PREPARE 'SELECT * FROM table where name = ?'
// EXECUTE stmt1, "foo"
proxy.Query(query, "bar")
// EXECUTE stmt1, "bar"
proxy.Query(query, "baz")
// EXECUTE stmt1, "baz"

Comparison

Inspired by: https://github.com/Masterminds/squirrel

Compared to squirrel, this pkg has:

• Better error handling
• Doesn't enforce squirrel-specific types like RowScanner
• Easier use with other pkgs that wrap or work with sql.DB
• Offers both a wrapper with additional fns, as well as caching proxy