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DDML, a language based on XML (Extensible Markup Language), allows you to logically define the entities you want to add to the Precise schema, such as tables, views, indexes, foreign keys, and all other required components. It covers the common entities available in most popular DBMSs.
After you have defined all database entities in DDML, you must run the DDML creation script to physically create the entities in the database.
General DDML document format
The general format of a DDML document looks as follows:
...
Root element of a DDML document. Its children are the main database entities:
<table-definition>
, <ddl-definition>
, and <view-definition>
. The <tables-definition>
tag includes the product attribute, which indicates the product of this specific DDML definition.
...
Includes the table-level attributes. Its children are the <column-definition>
, <index-definition>
, and <foreign-key-definition>
tags.
If a table is a statistics table, meaning means that the type attribute has the value STATISTICS, the <summary-hour>
, <summary-day>
, <summary-week>
, and <summary-month>
tags can be specified as children of the <table-definition>
tag.
...
<tables-definition> tag
Root element of the DDML document.
...
Required. Holds the product short name (product shortcut) consisting if two characters that define the product.
In this case, three custom-defined products are available:
C1
For customer-defined 1C2
For customer-defined 2C3
For customer-defined 3
<table-definition> tag
Holds all of the information included in a single table.
...
Required. Specifies the table type and can hold one of the following values:
- Statistics. A PMDB table that holds information about certain database activity, summarized into hours or time slices.
- Events. A PMDB table that keeps a log of database incidents.
...
Optional. Affects only Oracle and is developed as PCTFREE pctfree
.
Can have a value between 0 and 99.
...
the
...
database
...
.
...
Optional. Affects only Oracle and is developed as STORAGE(oracle-storage-clause)
. For example:
oracle-storage-clause="initial 1M next 1M minextents 1maxextents unlimited pctincrease 100"
...
The <table-definition>
tag can have the following
Children Display |
---|
<column-definition>
<index-definition>
<foreign-key-definition>
...
Optional. Instructs to define an hour-level summary table for this table. Used for time slice statistics tables.
The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions.
...
Optional. Instructs to define a day-level summary table for this table.
The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions.
...
Optional. Instructs to define a week-level summary table for this table.
The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions.
...
Optional. Instructs to define a month-level summary table for this table.
The name of the summary table is specified by the name attribute (required). The summary table name should follow the naming conventions specified in Naming conventions.
<ddl-definition> tag
Holds DDL (Data Definition Language) and DML (Data Manipulation Language) statements that can be performed during installation or uninstallation, such as stored procedures.
...
Optional. the RDBMS type on which the DDL generates. Must be one of the following:
oracle
mssql
""
If left empty (""), the DDL is created on all relational database management systems (RDBMS).
...
Optional. The RDBMS version on which the DDL generates. Should have the format 8.1. ...
If left empty, the DDL is created on all RDBMS versions.
...
Optional. The RDBMS version on which the DDL generates. Must be one of the following:
INSTALL
Default. During the installation process only.UNINSTALL
During the uninstallation process only.PREINSTALL
Before the installation process.PREUNINSTALL
Before the uninstallation process.
<view-definition> tag
Holds all the parameters required for a view definition.
...
Required. Specifies the view type and can hold one of the following values:
STATISTICS
A PMDB view that holds information about certain database activity, summarized into hours or time slices.INTERNAL
A PMDB view that keeps any other, non-statistical information.
...
<column-definition> tag
Holds all the parameters of a column.
...
Required. Holds the data type of a column:
BOOLEAN
Does not requiredata-length
ordata-scale
attributes. These attributes should not be specified. Implementation on all DBMSs:CHAR(1)
whereT
is the booleanTRUE
value andF
isFALSE
.
CHAR
Requiresdata-length
attribute. Implementation on all DBMSs:CHAR(data-length)
CLOB
Requiresdata-length
attribute. Implementation:TEXT
for Microsoft SQL ServerCLOB
for Oracle
DECIMAL
Requiresdata-length
(used for precision) anddata-scale
attributes. Implementation:NUMBER(data-length, data-scale)
for Microsoft SQL Server and IBM UDB Oracle
FLOAT
Requiresdata-length
attribute. Implementation:FLOAT(data-length)
for Microsoft SQL ServerNUMBER
without any parameters for Oracle
INTEGER
Requiresdata-length
attribute. Implementation:data-length
less than three:TINYINT
;data-length
two-to-four:SMALLINT
;data-length
more than four:BIGINT
for Microsoft SQL ServerNUMBER(data-length)
for Oracle
TIMESTAMP
Does not requiredata-length
ordata-scale
attributes. These attributes should not be specified. Implementation:DATETIME
for Microsoft SQL ServerTIME
for Oracle
UNIQUE INTEGER
Does not requiredata-length
ordata-scale
attributes. These attributes should not be specified. This is a data type for a unique integer whose values are generated automatically. Implementation:IDENTITY
for Microsoft SQL ServerNUMBER(20,0)
for Oracle. In addition, aSEQUENCE
and a TRIGGER BEFORE INSERT are created, which select theNEXTVAL
of theSEQUENCE
fromDUAL
.
VARCHAR
Requires thedata-length
attribute. Implementation:VARCHAR(data-length)
for Microsoft SQL ServerVARCHAR2(data-length)
for Oracle
VARBINARY
Requires thedata-length
attribute. Implementation:VARBINARY(data-length)
for Microsoft SQL ServerRAW(data-length)
for Oracle
...
Required only for the data types listed below. Specifies the column data length:
CHAR
CLOB
DECIMAL
FLOAT
INTEGER
VARCHAR
VARBINARY
...
Optional. Specifies the column default. Can have the following values:
NULL
if the column is nullable (null=TRUE).N/A
if no default exists. If the attribute is omitted, this is the default.
A constant value that is equal to the column type:
BOOLEAN TRUE
orFALSE
CHAR
A textual constant, such asABC CLOB
; a textual constant, such asABC DECIMAL
; or a decimal point constant, such as10.3
FLOAT
A floating point constant, such as12E7
INTEGER
An integer constant, such as27
TIMESTAMP
One of the following:- A timestamp constant of the format
yyyy-mm-dd hh:mm:ss.fffffffff
, which is jafa.sql.Timestamp’s format, such as2020-02-20 23:07:35:175000000
. Each DBMS displays a slightly different default. Implementation:2020-02-20 23:07:35:175
for Microsoft SQL ServerTO_DATE('2020-02-20 23:07:35')
for Oracle
- The literal string
CURRENT TIMESTAMP
. Implementation:GETDATE()
for Microsoft SQL ServerSYSDATE
for Oracle
- A timestamp constant of the format
UNIQUE INTEGER
Default value not required and not allowed.VARCHAR
A textual constant, such asABC
VARBINARY
A hex string where every two hexadecimal digits represent one byte, such asA07C889F
. Each DBMS displays a slightly different default. Implementation:0xA07C889F
for Microsoft SQL ServerHEXTORAW('A07C889F')
for Oracle
...
Required for the column role in columns of statistics tables. Can have the following values:
IDENTIFIER
A column identifying the sampled entity. The concatenation of all identifiers should uniquely identify the entity.DATE
A column identifying the sampled period. Its type should beTIMESTAMP
and be equal to the beginning of the sampled period.SUM
A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by theSUM
function.MIN
A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by theMIN
function.MAX
A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by theMAX
function.AVG
A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by theAVG
function.
Columns required for statistics tables
If the table is a statistics table, you must include the following columns:
<column-definition name=”<table shortcut>_TIMESTAMP” data-type=”TIMESTAMP” null=”FALSE” type=”DATE”/>
<column-definition name=”<table shortcut>_MINUTES_COUNT_SUM" data-type=”INTEGER” data-length=”9” null=”FALSE” type=”SUM” default=”1”/>
<column-definition name=”<table shortcut>_PWHG_ID” data-type=”INTEGER” data-length=”4” null=”FALSE” type=”IDENTIFIER”/>
<column-definition name=”<table shortcut>_PWII_INSTANCE_ID” data-type=”INTEGER” data-length=”9” null=”FALSE” type=”IDENTIFIER”/>
<column-definition name=”<table shortcut>_RECIEVED_TIMESTAMP” data-type=”TIMESTAMP” null=”FALSE” default=”CURRENT TIMESTAMP” type=”DATE”/>
Info |
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You must replace |
<index-definition> tag
Holds all the parameters for an index definition.
...
Required. Has the value TRUE
if this is a primary index and FALSE
if it is not. Implementation:
ALTER TABLE ADD CONSTRAINT
for Microsoft SQL Server. Adding a primary constraint in Microsoft SQL Server always results in creating a unique index to enforce the constraint.- An index is created using the
CREATE INDEX
statement for Oracle. Then anALTER TABLE ADD CONSTRAINT
is performed to add the primary constraint. TheALTER TABLE ADD CONSTRAINT
is suffixed with theUSING INDEX
clause to instruct Oracle to use the already created index to enforce the constraint and not to create a new one.
...
Optional. Has the value TRUE
if this is a clustered index and FALSE
if it is not. The default is FALSE
. A clustered index is an index that physically orders and organizes the table. Implementation:
CLUSTERED
clause for a clustered index,NON CLUSTERED
clause for a non-clustered index in Microsoft SQL Server.- In Oracle, this feature is not used frequently; it requires a complete entity to handle clustering.
...