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The CREATE TABLE statement declares a table in an Omnidex Environment File. Tables that are declared in an environment can then be indexed and retrieved using SQL statements. An Omnidex table can point to an underlying Oracle, SQL Server, MySQL or ODBC table or view. An Omnidex table can also point to one or more raw data files that match the column layout of the table.
The basic CREATE TABLE statement records information about the underlying table or raw data files in the Omnidex Environment Catalog, but it does not actually create an underlying relational table or raw data file. Normally, the relational table or view file is created using the relational database's tools. In the case of raw data files, the files are usually received from a data provider, and application or an ETL tool. The CREATE TABLE statement simply stores meta-data about the table in the Omnidex Environment File. Omnidex does support an exception to this rule for the creation of temporary tables.
The CREATE TABLE statement declares the characteristics of the table. At a minimum, each table has a name and instructions for accessing the physical data. Omnidex supports configuration settings for each table, including settings to for delimited files, data caches and index maintenance. Omnidex also provides rollup tables which pre-aggregate another table in the database and automatically optimize queries against the table.
The CREATE TABLE statement specifies the columns for a table. At a minimum, each column has a name and a datatype; however, it can also have other characteristics as well. Omnidex allows a column to have a different name than the one used in the underlying relational database. Omnidex allows the declaration of column usages that describe the purpose of the column. Omnidex also allows expression-based columns that are the result of a SQL expression, even if it does not exist in the underlying database or data file.
The CREATE TABLE statement specifies the constraints for a table. The most common constraints are primary and foreign constraints, used to declare parent-child relationships between tables. Omnidex allows constraints to be declared on both relational tables and raw data files, allowing either to be described using a full relational model. Omnidex allows these constraints to be declared, but it does not verify or enforce these constraints.
Like most databases, Omnidex allows indexes to be declared using the CREATE INDEX statement. For convenience, Omnidex also allows indexes to be declared using the CREATE TABLE statement. In most applications, many (if not all) of the columns are indexed with Omnidex, so it is convenient to declare the indexing directly in the table specification.
Omnidex allows constraints and indexing to be declared alongside each column. With inlining, the constraint and indexing specification is provided as each column is declared. This is a convenience for simple installations where most constraints and indexes consist of a single column.
CREATE [ < GLOBAL | LOCAL > ] TEMPORARY ] TABLE table [ NODE node] [ OPTIONS "options" ] [ PHYSICAL <"filespec" | rdbms_table> ] [ AUTOFILTER "criteria" ] [ DATA_CACHING < cache_size | DYNAMIC | NONE > ] [ PARTITION_BY "criteria" ] [ INDEX_MAINTENANCE <API | DBMS> ] ( column_specification, [ constraint_specification, ] [ index_specification, ] [ index_group_specification ] ) [ AS statement ] [ IN filename ] [ WITH options ]
column_name column_datatype [ PHYSICAL "physical_name" ] [ USAGE usage ] [ FORMAT format ] [ constraint_specification ] [ index_specification ] [ AS expression ],
Normal constraint definition:
[ CONSTRAINT constraint ] < PRIMARY [ KEY ] ( column [, column ... ] ) | UNIQUE [ KEY ] ( column [, column ... ] ) | DISTINCT [ KEY ] ( column [, column ... ] ) | FOREIGN [ KEY ] ( column [, column ... ] ) REFERENCES table [ ( column [, column ... ] ) ] [ PREJOIN ] >
Inlined constraint definition:
[ CONSTRAINT constraint ] < PRIMARY [ KEY ] | UNIQUE [ KEY ] | DISTINCT [ KEY ] | FOREIGN [ KEY ] REFERENCES table [ ( column [, column ... ] ) ] [ PREJOIN ] >
Normal index specification:
[ < OMNIDEX | QUICKTEXT | FULLTEXT | CUSTOM | NATIVE > [INDEX] ( < column | substring > [ , < column | substring > ... ] ) indexing_options
Inlined index specification:
[ < OMNIDEX | QUICKTEXT | FULLTEXT | CUSTOM | NATIVE > [INDEX] indexing_options
indexing_options:
Options available for OMNIDEX index: [ BITMAP ] [ STANDALONE ] [ < CASE_INSENSITIVE | CASE_SENSITIVE > ] Options available for QUICKTEXT indexes: [ < CASE_INSENSITIVE | CASE_SENSITIVE > ] Options available for FULLTEXT indexes: [ < CASE_INSENSITIVE | CASE_SENSITIVE > ] Options available for CUSTOM indexes: [ BITMAP ] [ STANDALONE ] [ KEYWORDING ] [ PROXIMITY ] [ < CASE_INSENSITIVE | CASE_SENSITIVE > ] [ EXCLUDED_WORDS ] [ PHONETIC ] [ PREJOIN table ] [ < RECORD_SPECIFIC | RECORD_COMPLEX > ]
INDEX GROUP [ ( owner ) ] group ( index [, index ... ] )
CREATE ENVIRONMENT and CREATE DATABASE have to be specified before specifying CREATE TABLE.
The IN “filespec.xml” clause has to be specified after the column definitions.
Tables must be declared in order of their constraints.
Parent tables should be declared before children tables.
Most CREATE TABLE statements will typically look like the following example where Omnidex indexing is specified after the column_name and column_type.
CREATE TABLE mytable PHYSICAL "mydir/mytable.dat" ( user_id INTEGER OMNIDEX, region CHARACTER(2) OMNIDEX, full_name CHARACTER(30) QUICKTEXT, address CHARACTER(60) QUICKTEXT, city CHARACTER(30) QUICKTEXT, state CHARACTER(2) OMNIDEX );
create table "HOUSEHOLDS" physical "dat\households*.dat" ( "HOUSEHOLD" character(12), "ADDRESS" character(50), "CITY" character(28), "STATE" character(2), "ZIP" character(5), "COUNTRY" character(2), constraint HOUSEHOLD_HOUSEHOLD_PK primay ("HOUSEHOLD"), constraint HOUSEHOLD_STATE_fk FOREIGN ("STATE") references "states", constraint HOUSEHOLDS_COUNTRY_FK foreign ("COUNTRY") references "COUNTRIES" ) in "simple.xml";
Here is the same CREATE TABLE statement as above but with the Omnidex Index type specified for each column.
create table "HOUSEHOLDS" physical "dat\households*.dat" ( "HOUSEHOLD" character(12) omnidex, "ADDRESS" character(50) quicktext, "CITY" character(28) quicktext, "STATE" character(2) omnidex, "ZIP" character(5) omnidex, "COUNTRY" character(2) omnidex, constraint HOUSEHOLD_HOUSEHOLD_PK primay ("HOUSEHOLD"), constraint HOUSEHOLD_STATE_fk FOREIGN ("STATE") references "states", constraint HOUSEHOLDS_COUNTRY_FK foreign ("COUNTRY") references "COUNTRIES" ) in "simple.xml";
Here is the same CREATE TABLE statement as above but with the Omnidex Index type specified for each column.
Additionally, it creates an Omnidex Composite index and combines the STATE and CITY columns into a single index.
create table "HOUSEHOLDS" physical "dat\households*.dat" ( "HOUSEHOLD" character(12) omnidex, "ADDRESS" character(50) quicktext, "CITY" character(28) quicktext, "STATE" character(2) omnidex, "ZIP" character(5) omnidex, "COUNTRY" character(2) omnidex, constraint HOUSEHOLD_HOUSEHOLD_PK primay ("HOUSEHOLD"), constraint HOUSEHOLD_STATE_fk FOREIGN ("STATE") references "states", constraint HOUSEHOLDS_COUNTRY_FK foreign ("COUNTRY") references "COUNTRIES" omnidex index "HSHD_STATE_CITY" ("STATE","CITY") ) in "simple.xml";
There are three types of Omnidex indexes called Omnidex, QuickText, and FullText.
The following table shows the key types of retrieval properties of these Omnidex index types.
Omnidex | QuickText | FullText | Custom | |
---|---|---|---|---|
Criteria | Yes | Yes | Yes | |
Counts | Yes | Yes | Yes | |
Sum, Average, Min, Max | Yes | No | No | |
Table Joins | Yes | No | No | |
Group By | Yes | No | No | |
Order By | Yes | No | No | |
Geographic Searches | Yes | No | No | |
Textual Searches | No | Yes | Yes | |
Proximity Searches | No | No | Yes | |
Relevancy Scoring | No | No | Yes | |
Indexing Overhead | Low | Low | High |
In addition to the three basic Omnidex Index Types: Omnidex, QuickText, and FullText, there is a Custom Index Type that can be used to specify advanced indexing options.
Omnidex supports the following standard datatypes:
Datatype | Description |
---|---|
CHARACTER(n) | Space-filled character string of n characters |
CHAR(n) | Synonym for CHARACTER(n) |
C STRING(n) | Null-terminated character string of n characters |
VARCHAR(n)* | String of max n characters, with length variable |
CLOB(n)* | Character large object of max n characters, with length variable |
[SIGNED] TINYINT | 1-byte, signed integer ( -128 to 127 ) |
UNSIGNED TINYINT | 1-byte, unsigned integer ( 0 to 255 ) |
[SIGNED] SMALLINT | 2-byte, signed integer ( -32768 to 32767 ) |
UNSIGNED SMALLINT | 2-byte, unsigned integer ( 0 to 65535 ) |
[SIGNED] INTEGER | 4-byte, signed integer ( 2147483648 to 2147483647 ) |
UNSIGNED INTEGER | 4-byte, unsigned integer ( 0 to 4294967295 ) |
[SIGNED] BIGINT | 8-byte, signed integer ( -2^63 to 2^63-1 ) |
UNSIGNED BIGINT | 8-byte, unsigned integer ( 0 to 2^64-1 ) |
FLOAT | IEEE four-byte, single-precision floating point |
DOUBLE | IEEE eight-byte, double-precision floating point |
DATE | 10-byte ANSI date |
TIME | 11-byte ANSI time |
DATETIME | 24-byte ANSI datetime |
ASCII DATE | 8-byte ASCII date ( YYYYMMDD ) |
ASCII DATE(6) | 6-byte ASCII date ( YYMMDD ) |
ODBC DATE | 6-byte ODBC proprietary date |
ODBC TIME | 6-byte ODBC proprietary time |
ODBC DATETIME | 6-byte ODBC proprietary datetime |
ORACLE DATE | 7-byte Oracle proprietary date |
ORACLE TIME | 7-byte Oracle proprietary time |
ORACLE DATETIME | 7-byte Oracle proprietary datetime |
OMNIDEX DATE(n) | Omnidex proprietary date supporting n digits of YYYYMMDD |
OMNIDEX TIME(n) | Omnidex proprietary time supporting n digits of HHMMSSNN |
OMNIDEX DATETIME(n) | Omnidex proprietary datetime supporting n digits of YYYYMMDDHHMMSSNN |
* Omnidex recommends use of the CHARACTER and C STRING datatypes rather than VARCHAR and CLOB due to the requirement of a length variable. |
Omnidex also provides partial support for National Character Datatypes (sometimes called Unicode datatypes or wide characters). The Omnidex SQL Engine will process these datatypes, but the Omnidex Indexing Engine will only index the lower 8 bits of these datatypes.
Datatype | Description |
---|---|
NATIONAL CHARACTER(n) | Space-filled character string of n characters |
NATIONAL CHAR(n) | Synonym for CHARACTER(n) |
NATIONAL C STRING(n) | Null-terminated character string of n characters |
NATIONAL VARCHAR(n)* | String of max n characters, with length variable |
NATIONAL CLOB(n)* | Character large object of max n characters, with length variable |
* Omnidex recommends use of the NATIONAL CHARACTER and NATIONAL C STRING datatypes rather than NATIONAL VARCHAR and NATIONAL CLOB due to the requirement of a length variable. |