Integration: Raw Data Files

Omnidex Standalone Tables

Options Used in CREATE TABLE Statements

The OPTIONS clause of the CREATE TABLE statement is used to indicate that these files are Omnidex Standalone Tables. The only option used in this clause is the OST option described below:

OST
OST

The OST option identifies this file as an Omnidex Standalone Table.


Options Used in EXPORT Statements

The OST option described above would also be used on EXPORT statements to cause an Omnidex Standalone Table to be created. There are other options that are used in EXPORT statements that control the features used in Omnidex Standalone Tables. These options are not redundantly declared in the CREATE TABLE statement, and are only used in the EXPORT statement.

OST
OST

The OST option identifies this file as an Omnidex Standalone Table.

INDEXBY
INDEXBY='col1[,col2...][;col3[,col4...] ...]'

The INDEXBY option causes the Omnidex Standalone Table to be created with internal indexes. These are not Omnidex indexes, but instead are hashed indexes that are contained within the Omnidex Standalone Table. These hashed indexes are often applied to primary or foreign keys within the Omnidex Standalone Table. The INDEXBY option can declare multiple indexes separated by semicolons. Each index can consist of multiple columns separated by commas.

Any indexes within the Omnidex Standalone Table must also be declared as NATIVE indexes in the CREATE TABLE or CREATE INDEX statement. If they are not declared as NATIVE indexes, Omnidex will not take advantage of those indexes when optimizing queries.

Omnidex Standalone Tables that have native indexes cannot be updated using INSERT, DELETE or UPDATE statements. Only Omnidex Standalone Tables without native indexes support INSERT, DELETE and UPDATE statements.

NULL_INDICATORS
NULL_INDICATORS=< ON | OFF >

The NULL_INDICATORS option declares whether the Omnidex Standalone Table should use null-indicators internally. Null indicators differentiate whether a particular column for a particular row contains no value, referred to as a NULL column. Relational databases typically support null indicators; however, raw data files do not. If null indicators will not be needed, then use this option to turn them off. This will save one bit per column per row, reducing disk space and improving performance.

DELETES
DELETES=< ON | OFF >

The DELETES option declares whether the Omnidex Standalone Table should use delete flags internally. Delete flags indicate whether a row within the table has been deleted and is eligible for reuse by a future insert. If deletes will not be needed, then use this option to turn deletes off. This will save one byte per row, reducing disk space and improving performance.

COMPRESSION
COMPRESSION=< ON | OFF >

The COMPRESSION option declares whether the Omnidex Standalone Table should use compression internally. Compression eliminates wasted space in large text columns, but requires some overhead to manage. If compression will not be needed, then use this option to turn compression off. This will reduce the size of each row, reducing disk space and improving performance.

Additional Resources

See also:

 
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integration/rawdata/ost/options.txt ยท Last modified: 2016/06/28 22:38 (external edit)
 
 
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