DB driver feature matrix:

Symbols:
  "x" - implemented, but without tests
  "t" - implemented, but one or more tests fail
  "T" - implemented, passing all tests
  "e" - emulated, without tests
  "E" - emulated, passing all tests
  "n" - returns "not capable"
  "-" - no implementation of this feature


                   fbsql      ifx      mssql      oci8     pgsql
FEATURE              |  ibase  |  msql   |   mysql |   odbc  |  sybase
simpleQuery          x    x    x    x    x    T    T    x    T    x
numCols              x    x    x    x    x    T    T    x    T    x
numRows              x    n    n    x    x    T    E    n    T    n
errorNative          x    n    x    n    n    T    x    x    T    n
prepare/execute      e    x    e    e    e    E    T    e    E    e
sequences            e    n    n    n    n    E    T    n    T    n
affectedRows         x    n    x    n    n    T    T    n    T    n
fetch modes          x    x    x    x    x    T    T    x    T    x
fetch absolute rows  x    n    x    x    x    x    n    x    x    x
transactions         x    x    n    n    n    n    x    x    x    n
auto-commit          x    x    n    n    n    n    x    x    x    n
error mapping        x    -    e    -    -    T    T    x    E    -
tableInfo            x    n    n    n    n    T    n    n    n    n