Sybase 12.4.2 - Manual (Page 96)

Connection parameters
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• The entries in a connection string are read left to right. If the same
parameter is specified more than once, the last one in the string
applies.
• If a string contains a DSN or FILEDSN entry, the profile is read from
the configuration file, and the entries from the file are used if they are
not already set. For example, if a connection string contains a data
source name and sets some of the parameters contained in the data
source explicitly, then in case of conflict the explicit parameters are
used.
Connection parameter priorities
Connection parameters often provide more than one way of accomplishing a
given task. This is particularly the case with embedded databases, where a
database server is started by the connection string.
For example, if your connection starts a database, you can specify the database
name using the DBN connection parameter or using the DBS parameter.
Here are some recommendations and notes for situations where connection
parameters conflict:
• Specify database files using DBF You can specify a database file on
the Start parameter or using the DBF parameter. DBF is recommended.
• Specify database names using DBN You can specify a database
name on the Start parameter, the DBS parameter, or using the DBN
parameter. DBN is recommended.
• Use the Start parameter to specify cache size Even though you
use the DBF connection parameter to specify a database file, you may still
want to tune the way in which it starts. You can use the Start parameter to
do this.
For example, if you are using the Java features of Adaptive Server IQ, you
should provide additional cache memory for the Catalog Store on the Start
parameter. The following sample set of embedded database connection
parameters describes a connection that may use Java features:
DBF=path\asademo.db
DBN=Sample
ENG=Sample Server
UID=DBA
PWD=SQL
Start=asiqsrv12 -c 8M