Filter
Top Products
Product Environment 9-7
What Is Multiple Residency?
Blob Scanning or Compression
OnLine receives blob data into an existing table in any one of four ways:
■ From the DB-Access LOAD statement
■ From the OnLine dbload utility
■ From INFORMIX-ESQL/C locator variables
■ From INFORMIX-ESQL/C FILE host data types
OnLine does not contain any mechanisms for scanning blobs and inserting
the data into a file, or for blob compression, after the blob has been scanned.
What Is Multiple Residency?
Multiple OnLine database servers and separate collections of OnLine shared
memory and disk structures can coexist on a single host machine. During
processing, each OnLine database server process on the host machine reads
the TBCONFIG environment variable for the name of its configuration file.
Next, the database server process reads its configuration file to obtain the
value of its SERVERNUM parameter. The SERVERNUM parameter is part of the
calculation that defines the shared-memory segment to which this database
server process should attach. In this way, the TBCONFIG environment
variable maintains independent shared-memory segments. (Refer to
page 9-10.)
Your ability to create independent database server environments on the same
host machine offers you the following options:
■ Create separate but parallel OnLine production and OnLine devel-
opment environments.
If you separate production and development environments, users
can protect the production system from the unpredictable nature of
the development environment. Archiving, shared-memory utiliza-
tion, and tuning priorities can reflect the needs of each specific
environment.