# McoSqlOpenParameters:OpenFlags

The possible values for McoSqlOpenParameters `flags` property.

### For an overview see page McoSqlOpenParameters

The OpenFlags enum defines the values listed below.

ALLOCATE_MEMORY = 1 | Allocate memory buffer of specified size for eXtremeDB database using the `malloc()` function (the value of the `mapAddress` parameter is ignored). If this flag is not set, the specified value of the `mapAddress` parameter is used. This flag is ignored for shared memory database, in which case `mapAddress` always specifies the mapping address.
SET_ERROR_HANDLER = 2 | Set the McoSql specific error handler.
START_MCO_RUNTIME = 4 | Start the eXtremeDB runtime.
INITIALIZE_DATABASE = 16 | Initialize a new database instance; i.e. call `mco_db_open_dev()`.
PRESERVE_SHARED_DATABASE = 32 | Do not close database, keeping it in shared memory
FOREIGN_CONNECTION = 64 | A connection was established outside McoSqlEngine; do not perform disconnect and database close
DEFAULT_OPEN_FLAGS | Set to `ALLOCATE_MEMORY | SET_ERROR_HANDLER | START_MCO_RUNTIME | INITIALIZE_DATABASE`