Contents
-
+
- Relationship to other standards
- olap4j and XML/A
- olap4j is built on other standards @@ -149,6 +147,17 @@
- Other methods
Contents
- Transform +
- Query model details +
- Navigation actions + +
- Open issues +
- Layout
-
+
1.1. A brief history of OLAP sta
query language. A query language is easier to explain than an API. It leaves
unsolved the problem of how to construct queries to answer business questions,
but application developers could solve that problem by embedding one of the
-off-the-shelf OLAP clients.
+off-the-shelf OLAP clients.
The Open Source community has been developing a taste for OLAP. First there was Mondrian, an open-source OLAP
server; then there was JPivot, a client which first spoke to Mondrian, then also
@@ -252,21 +261,29 @@
1.2. Overview of olap4j
higher-level query model, which includes operations to transform queries
(also called 'navigations'), and facilities to layout multidimensional results as HTML tables.
-1.3. Relationship to other
-standards
+1.3. Relationship to other standards
+
1.3.1. olap4j and XML/A
At this point, you may be saying: what about XML/A? XML/A was here first, is an
open standard, and is supported by a number of servers. Is olap4j an attempt to
replace XML/A? Isn't XML/A good enough for everyone?
-olap4j certainly has some similarities with XML/A. Both APIs allow an application to execute OLAP queries, and to browse the metadata of an OLAP schema. But XML/A is a
-low-level web-services API which leaves a lot of work to the application writer.
-(Witness the fact that the majority of successful XML/A applications run only on
-Windows, where the ADOMD.NET is a high-level interface to XML/A servers.)
+
olap4j certainly has some similarities with XML/A. Both APIs allow
+an application to execute OLAP queries, and to browse the metadata of
+an OLAP schema. But XML/A is a
+low-level web-services API which leaves a lot of work to the
+application writer.
+(Witness the fact that the majority of successful XML/A applications
+run only on
+Windows, where the ADOMD.NET is a high-level interface to XML/A
+servers.)
The APIs are mostly complementary, because olap4j can be easily
-added to an XML/A back-end, and provides features which would be difficult or
-impossible to provide via a web-services API. These are functions for parsing MDX, building and transforming MDX query models, and mapping result sets into
+added to an XML/A back-end, and provides features which would be
+difficult or
+impossible to provide via a web-services API. These are functions for
+parsing MDX, building and transforming MDX query models, and mapping
+result sets into
graphical layouts such as pivot tables.
If a web-services based application needs these functions, it can use the
@@ -326,20 +343,20 @@
1.5. Architecture of olap4j
1.6. Compatibility
-olap4j requires JDK 1.5 or higher, in particular because it uses the generics
+
olap4j requires JDK 1.5 or higher, in particular because it uses the generics
and enum features introduced in JDK 1.5.0.
JDK 1.4 compability will be available on demand, using the
-Retroweaver utility. This will
-consist of a retrowoven JAR file, olap4j-jdk1.4.jar and
+Retroweaver utility. This will
+consist of a retrowoven JAR file, olap4j-jdk1.4.jar and
retroweaver's runtime library retroweaver-rt-1.2.4.jar. (See
design note.)
-jdbc is consistent with JDBC version 3.0 (which was introduced in JDK 1.4 and
+
jdbc is consistent with JDBC version 3.0 (which was introduced in JDK 1.4 and
is also in JDK 1.5).
-JDBC version 4.0 is expected to be introduced in JDK 1.6.0. We expect JDBC
-4.0 will add new methods to existing JDBC classes, and therefore compatibility
+
JDBC version 4.0 is expected to be introduced in JDK 1.6.0. We expect JDBC
+4.0 will add new methods to existing JDBC classes, and therefore compatibility
with JDBC 4.0 will require a new release of olap4j.
@@ -349,8 +366,9 @@
We now describe the olap4j API in more detail, by breaking it down into a set
of functional areas.
-
-2.1. Driver management
+
+
+2.1. Driver management
olap4j shares JDBC's driver management facilities. This allows olap4j clients
to leverage the support for JDBC such as
@@ -369,7 +387,7 @@
2.1.1. Driver
Same functionality as JDBC.
Here is an example of registering an olap4j driver:
- Class.forName("mondrian.olap4j.Driver");
+ Class.forName("mondrian.olap4j.Driver");
2.1.2. DriverManager
Same functionality as JDBC.
2.1.3. DataSource
@@ -381,7 +399,7 @@ 2.2. Connections
statements.
Where possible, olap4j uses JDBC's session management facility. olap4j defines extensions to
-JDBC interfaces Connection and Statement.
+JDBC interfaces Connection and Statement.
For example, the following code registers a driver, connects to Mondrian and
executes a statement:
@@ -424,7 +442,7 @@ 2.2. Connections
Package name: org.olap4j
-2.2.1. OlapConnection
+2.2.1. OlapConnection
OlapConnection (extends
@@ -434,13 +452,14 @@
2.2.1. OlapConnection
2.2.2. Connection pooling
-Look again at the code samples in the previous section. One would expect that it would be safe to downcast the result of a factory
+
Look again at the code samples in the previous section. One would
+expect that it would be safe to downcast the result of a factory
method to the desired result. For example, if you invoke an OlapConnection's
createStatement() method, the result should be an
OlapStatement.
But if you you are using a connection-pooling
-library (common examples of which include Jakarta Commons DBCP
+library (common examples of which include Jakarta Commons DBCP
and
C3P0), this is not so. Every
connection-pooling library tracks connections by wrapping them in another class,
@@ -451,7 +470,7 @@
2.2.2. Connection pooling
If you are using a connection-pooling library, olap4j provides a helper class to access the object underneath a wrapped
connection, statement, prepared statement or result set. For instance,
-DataSource dataSource; // a data source using a connection
+DataSource dataSource; // a data source using a connection
pool
Connection connection =
DriverManager.createConnection(
@@ -465,16 +484,16 @@ 2.2.2. Connection pooling
The
-Olap4j.convert(Connection) method returns an OlapConnection. It
-works with common connection pools, and the resulting object is instrumented so
-that any statements or prepared statements created from that connection also
+Olap4j.convert(Connection) method returns an OlapConnection. It
+works with common connection pools, and the resulting object is instrumented so
+that any statements or prepared statements created from that connection also
work with the connection pool.
The problem does not just affect connections: some connection pools also wrap
Statement, PreparedStatement, ResultSet
-and DatabaseMetaData objects, so there are convert()
+and DatabaseMetaData objects, so there are convert()
methods for these too.
-Hopefully this problem will only be temporary. As olap4j gains popularity, we
-expect connection pools to add support for the extended interfaces, and it will
+
Hopefully this problem will only be temporary. As olap4j gains popularity, we
+expect connection pools to add support for the extended interfaces, and it will
be sufficient merely to cast the objects returned from factory methods.
2.3. Statements
@@ -565,31 +584,31 @@ 2.4. MDX query model
Query query = new Query();
query.setFrom("Sales");
query.getAxes().add(
- new Axis(
- "ROWS",
- false,
- new UnresolvedFunCall(
- "{}",
-
+ new Axis(
+ "ROWS",
+ false,
+ new UnresolvedFunCall(
+ "{}",
+
Syntax.Special,
- new Id(new
- String[] {"Measures", "Unit Sales"})));
+ new Id(new
+ String[] {"Measures", "Unit Sales"})));
// Create a statement based upon the query model.
OlapStatement stmt;
try {
- stmt = connection.createOlapStatement(query);
+ stmt = connection.createOlapStatement(query);
} catch (OlapException e) {
- System.out.println("Validation failed: " + e);
- return;
+ System.out.println("Validation failed: " + e);
+ return;
}
// Execute the statement.
ResultSet rset;
try {
- rset = stmt.execute();
+ rset = stmt.execute();
} catch (OlapException e) {
- System.out.println("Execution failed: " + e);
+ System.out.println("Execution failed: " + e);
}
Package name: org.olap4j.mdx
@@ -619,7 +638,8 @@ 2.5. MDX type model
Here are some examples:
-
+
+
Expression
Type
@@ -644,6 +664,7 @@ 2.5. MDX type model
[Store].[USA].Children(2)Member<dimension=[Store], hierarchy=[Store], level=[Store].[State]>
+
Since MDX is a late-binding language, some expressions will have unknown
@@ -651,7 +672,7 @@
2.5. MDX type model
- [Store].Levels("Sta" + "te")
+ [Store].Levels("Sta" + "te")
will have type Level<dimension=[Store], level=unknown>. The
validator knows that the <hierarchy>.Levels(<string expr>) function
@@ -671,28 +692,31 @@
2.5. MDX type model
DecimalType (extends NumericType) represents a fixed-point numeric expression. It
is a subclass of NumericType, and has precision and scale. An
integer expression would have scale 0.
-
olap4j-jdk1.4.jar and
+Retroweaver utility. This will
+consist of a retrowoven JAR file, olap4j-jdk1.4.jar and
retroweaver's runtime library retroweaver-rt-1.2.4.jar. (See
design note.)OlapConnection's
createStatement() method, the result should be an
OlapStatement.Connection connection =
DriverManager.createConnection(
@@ -465,16 +484,16 @@
2.2.2. Connection pooling
The
-Olap4j.convert(Connection) method returns an OlapConnection. It
-works with common connection pools, and the resulting object is instrumented so
-that any statements or prepared statements created from that connection also
+Olap4j.convert(Connection) method returns an OlapConnection. It
+works with common connection pools, and the resulting object is instrumented so
+that any statements or prepared statements created from that connection also
work with the connection pool.
The problem does not just affect connections: some connection pools also wrap
Statement, PreparedStatement, ResultSet
-and DatabaseMetaData objects, so there are convert()
+and DatabaseMetaData objects, so there are convert()
methods for these too.
Hopefully this problem will only be temporary. As olap4j gains popularity, we -expect connection pools to add support for the extended interfaces, and it will +
Hopefully this problem will only be temporary. As olap4j gains popularity, we +expect connection pools to add support for the extended interfaces, and it will be sufficient merely to cast the objects returned from factory methods.
2.3. Statements
@@ -565,31 +584,31 @@2.4. MDX query model
Query query = new Query();query.setFrom("Sales");
query.getAxes().add(
- new Axis(
- "ROWS",
- false,
- new UnresolvedFunCall(
- "{}",
- + new Axis(
+ "ROWS",
+ false,
+ new UnresolvedFunCall(
+ "{}",
+ Syntax.Special,
- new Id(new - String[] {"Measures", "Unit Sales"})));
+ new Id(new + String[] {"Measures", "Unit Sales"})));
// Create a statement based upon the query model.
OlapStatement stmt;
try {
- stmt = connection.createOlapStatement(query);
+ stmt = connection.createOlapStatement(query);
} catch (OlapException e) {
- System.out.println("Validation failed: " + e);
- return;
+ System.out.println("Validation failed: " + e);
+ return;
}
// Execute the statement.
ResultSet rset;
try {
- rset = stmt.execute();
+ rset = stmt.execute();
} catch (OlapException e) {
- System.out.println("Execution failed: " + e);
+ System.out.println("Execution failed: " + e);
}
Package name: org.olap4j.mdx
@@ -619,7 +638,8 @@2.5. MDX type model
Here are some examples:
| Expression | Type | [Store].[USA].Children(2) |
Member<dimension=[Store], hierarchy=[Store], level=[Store].[State]> | +
|---|
Since MDX is a late-binding language, some expressions will have unknown @@ -651,7 +672,7 @@
2.5. MDX type model
Level<dimension=[Store], level=unknown>. The
validator knows that the <hierarchy>.Levels(<string expr>) function
@@ -671,28 +692,31 @@ ASC
+ ASC
keyword in the expression Order(Gender.MEMBERS, Measures.[Unit Sales],
ASC) is a symbol. Symbol types are rarely used except if you are
manipulating a parse tree.Metadata types:
-
-
- CubeType represents the type of an expression whose value - is a cube. +
- CubeType + represents the type of an expression whose value is a cube.
- DimensionType represents the type of an expression whose value is a dimension.
- HierarchyType represents the type of an expression whose value is a hierarchy. -
- LevelType represents the type of an expression whose value - is a level. -
- MemberType represents the type of an expression whose value - is a member. +
- LevelType + represents the type of an expression whose value is a level. +
- MemberType + represents the type of an expression whose value is a member.
A metadata type may be constrained to a particular part of the schema. For
example, LevelType(hierarchy=[Time]) indicates that the expression
@@ -841,7 +865,8 @@
2.6.3. Methods which return sc olap4j method.
| XML for Analysis schema rowset | OlapDatabaseMetaData method |
|---|
The rows returned in the result set returned from the metadata methods are structured according to the result set column layouts detailed in this @@ -961,8 +986,8 @@
2.6.3. Methods which return sc column.
| Column heading | +|
|---|---|
| Column heading | Contents |
[Need to clean up data types in the following tables. Types should all be JDBC types.]
[Need to clean up column names in the following tables. Columns should be @@ -1012,7 +1037,7 @@
2.6.3.1. getDatasources
The returned result set contains the following columns.
| Column name | Type | Description | @@ -1055,7 +1080,7 @@Yes | string |
The name of the provider behind the data source. -Example: Example: |
Yes | @@ -1109,7 +1134,7 @@No | -
|---|
2.6.3.2. getDatabaseProperties
@@ -1121,7 +1146,7 @@2.6.3.2. getDatabaseProperties
The returned result set contains the following columns.
| Column name | Type | Description | @@ -1184,7 +1209,7 @@Yes |
|---|
[Is VALUE a JDBC reserved word? If so, change it.]
@@ -1195,7 +1220,7 @@2.6.3.3 getLiterals
The returned result set contains the following columns.
| Column name | Type | Description | @@ -1218,7 +1243,7 @@No | @@ -1266,7 +1291,7 @@Yes |
|---|
2.6.3.4. getCubes
@@ -1275,7 +1300,7 @@2.6.3.4. getCubes
The returned result set contains the following columns.
| Column name | Type indicator | Description | @@ -1379,7 +1404,7 @@DBTYPE_WSTR | (Optional) A set of notes, in XML format. |
|---|
The rowset is sorted on CATALOG_NAME, SCHEMA_NAME, CUBE_NAME.
@@ -1391,7 +1416,7 @@2.6.3.5. getDimensions
The returned result set contains the following columns.
| Column name | Type indicator | Description | @@ -1490,8 +1515,10 @@IS_READWRITE | DBTYPE_BOOL | A Boolean that indicates whether the dimension
- is write-enabled. TRUE if the dimension is - write-enabled. |
+ is write-enabled.
+
+
|---|---|---|---|---|---|
| DIMENSION_UNIQUE_SETTINGS | @@ -1515,7 +1542,7 @@DBTYPE_BOOL | Always TRUE. |
The result set is sorted on CATALOG_NAME, SCHEMA_NAME, CUBE_NAME, DIMENSION_NAME.
@@ -1528,7 +1555,7 @@2.6.3.6. getFunctions
The returned result set contains the following columns.
| Column name | Type indicator | Description | @@ -1570,7 +1597,7 @@DBTYPE_WSTR | The name of the interface for user-defined
functions The group name for Multidimensional - Expressions (MDX) functions. |
+ Expressions (MDX) functions.
|---|---|---|---|---|
| LIBRARY_NAME | @@ -1583,7 +1610,7 @@DBTYPE_WSTR | (Optional) The name of the assembly that
implements the user-defined function. Returns - VT_NULL for MDX functions. |
+ VT_NULL for MDX functions.
||
| HELP_FILE | @@ -1591,7 +1618,7 @@(Optional) The name of the file that contains
the help documentation for the user-defined
function. Returns VT_NULL for MDX - functions. |
+ functions.
|||
| HELP_CONTEXT | @@ -1605,16 +1632,16 @@(Optional) The generic name of the object class
to which a property applies. For example, the rowset
corresponding to the <level_name>.Members function
- returns "Level". Returns VT_NULL for + returns "Level". Returns VT_NULL for user-defined functions, or non-property MDX - functions. |
+ functions.
|||
| CAPTION | DBTYPE_WSTR | The display caption for the function. |
The rowset is sorted on ORIGIN, INTERFACE_NAME, FUNCTION_NAME.
@@ -1626,7 +1653,7 @@2.6.3.7. getHierarchies
The returned result set contains the following columns.
| Column name | Type indicator | Description | @@ -1756,7 +1783,7 @@A Boolean that indicates whether the Write Back
to dimension column is enabled. Returns TRUE if the Write Back to dimension column that - represents this hierarchy is enabled. |
+ represents this hierarchy is enabled.
|---|---|---|---|
| DIMENSION_UNIQUE_SETTINGS | @@ -1792,7 +1819,7 @@DBTYPE_BOOL | A Boolean that indicates whether the hieararchy
is visible. Returns TRUE if the hierarchy - is visible; otherwise, FALSE. |
+ is visible; otherwise, FALSE.
|
| HIERARCHY_ORIGIN | @@ -1810,7 +1837,7 @@|||
| HIERARCHY_DISPLAY_FOLDER | @@ -1834,7 +1861,7 @@
The rowset is sorted on CATALOG_NAME, SCHEMA_NAME, CUBE_NAME, DIMENSION_UNIQUE_NAME, @@ -1845,7 +1872,7 @@
2.6.3.8. getLevels
Specified by the MDSCHEMA_LEVELS XML for Analysis method.
The returned result set contains the following columns.
| Column name | Type indicator | Description | @@ -2006,7 +2033,7 @@A Boolean that indicates whether the level is
visible. Always returns True. If the level is not visible, it will not be included in the schema - rowset. |
+ rowset.
|---|---|---|---|
| LEVEL_ORDERING_PROPERTY | @@ -2020,7 +2047,7 @@The DBTYPE enumeration of the member key
column that is used for the level attribute. Null if concatenated keys are used as the member key - column. |
+ column.
||
| LEVEL_MASTER_UNIQUE_NAME | @@ -2072,7 +2099,7 @@
The rowset is sorted on CATALOG_NAME, SCHEMA_NAME, CUBE_NAME, DIMENSION_UNIQUE_NAME, @@ -2083,7 +2110,7 @@
2.6.3.9. getMeasures
Specified by the MDSCHEMA_MEASURES XML for Analysis method.
The returned result set contains the following columns.
| Column name | Type indicator | Length | @@ -2092,7 +2119,7 @@|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CATALOG_NAME | DBTYPE_WSTR | -+ | The name of the catalog to which this measure belongs. NULL if the provider does not support catalogs. | @@ -2100,7 +2127,7 @@||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| SCHEMA_NAME | DBTYPE_WSTR | -+ | The name of the schema to which this measure belongs. NULL if the provider does not support schemas. | @@ -2108,20 +2135,20 @@||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CUBE_NAME | DBTYPE_WSTR | -+ | The name of the cube to which this measure belongs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEASURE_NAME | DBTYPE_WSTR | -+ | The name of the measure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEASURE_UNIQUE_NAME | DBTYPE_WSTR | -+ | The Unique name of the measure. For providers that generate unique names by qualification, each component of this name is delimited. | @@ -2129,7 +2156,7 @@||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEASURE_CAPTION | DBTYPE_WSTR | -+ | A label or caption associated with the measure. Used primarily for display purposes. If a caption does not exist, MEASURE_NAME is returned. | @@ -2137,13 +2164,13 @@||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEASURE_GUID | DBTYPE_GUID | -+ | Not supported. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEASURE_AGGREGATOR | DBTYPE_I4 | -+ | An enumeration that identifies how a measure was
derived. Can be one of the following values:
2.6.3.9. getMeasuresDATA_TYPE |
DBTYPE_UI2 |
- |
+ |
The data type of the measure. |
NUMERIC_PRECISION |
DBTYPE_UI2 |
- |
+ |
The maximum precision of the property if the
measure object's data type is exact numeric. NULL
for all other property types. |
@@ -2184,7 +2211,7 @@ 2.6.3.9. getMeasuresNUMERIC_SCALE |
DBTYPE_I2 |
- |
+ |
The number of digits to the right of the decimal
point if the measure object's type indicator is
DBTYPE_NUMERIC or DBTYPE_DECIMAL.
@@ -2193,26 +2220,26 @@ | 2.6.3.9. getMeasuresMEASURE_UNITS |
DBTYPE_WSTR |
- |
+ |
Not supported |
DESCRIPTION |
DBTYPE_WSTR |
- |
+ |
A human-readable description of the measure.
NULL if no description exists. |
EXPRESSION |
DBTYPE_WSTR |
- |
+ |
An expression for the member. |
MEASURE_IS_VISIBLE |
DBTYPE_BOOL |
- |
+ |
A Boolean that always returns True. If the
measure is not visible, it will not be included in
the schema rowset. |
@@ -2220,34 +2247,34 @@ 2.6.3.9. getMeasuresLEVELS_LIST |
DBTYPE_WSTR |
- |
+ |
A string that always returns NULL. |
MEASURE_NAME_SQL_COLUMN_NAME |
DBTYPE_WSTR |
- |
+ |
The name of the column in the SQL query that
corresponds to the measure's name. |
MEASURE_UNQUALIFIED_CAPTION |
DBTYPE_WSTR |
- |
+ |
The name of the measure, not qualified with the
measure group name. |
MEASUREGROUP_NAME |
DBTYPE_WSTR |
- |
+ |
The name of the measure group to which the
measure belongs. |
MEASURE_DISPLAY_FOLDER |
DBTYPE_WSTR |
- |
+ |
The path to be used when displaying the measure
in the user interface. Folder names will be
separated by a semicolon. Nested folders are
@@ -2256,10 +2283,10 @@ | 2.6.3.9. getMeasuresDEFAULT_FORMAT_STRING |
DBTYPE_WSTR |
- |
+ |
The default format string for the measure. |
|
The rowset is sorted on CATALOG_NAME, SCHEMA_NAME, CUBE_NAME, MEASURE_NAME.
@@ -2270,7 +2297,7 @@2.6.3.10. getMembers
The returned result set contains the following columns.
| Column name | Type indicator | Length | @@ -2279,74 +2306,74 @@||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CATALOG_NAME | DBTYPE_WSTR | -+ | The name of the database to which this member belongs. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| SCHEMA_NAME | DBTYPE_WSTR | -+ | The name of the schema to which this member belongs. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CUBE_NAME | DBTYPE_WSTR | -+ | The name of the cube to which this member belongs. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DIMENSION_UNIQUE_NAME | DBTYPE_WSTR | -+ | The unique name of the dimension to which this member belongs. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HIERARCHY_UNIQUE_NAME | DBTYPE_WSTR | -+ | The unique name of the hierarchy to which this member belongs. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| LEVEL_UNIQUE_NAME | DBTYPE_WSTR | -+ | The unique name of the level to which this member belongs. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| LEVEL_NUMBER | DBTYPE_UI4 | -+ | The distance of the member from the root of the hierarchy. The root level is zero (0). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEMBER_ORDINAL | DBTYPE_UI4 | -+ | (Deprecated) Always returns 0. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEMBER_NAME | DBTYPE_WSTR | -+ | The name of the member. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEMBER_UNIQUE_NAME | DBTYPE_WSTR | -+ | The unique name of the member. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MEMBER_TYPE | DBTYPE_I4 | -+ | The type of the member:
2.6.3.10. getMembersMEMBER_GUID |
DBTYPE_GUID |
- |
+ |
The GUID of the member. NULL if no GUID
exists. |
MEMBER_CAPTION |
DBTYPE_WSTR |
- |
+ |
A label or caption associated with the member.
Used primarily for display purposes. If a caption
does not exist, MEMBER_NAME is returned. |
@@ -2380,7 +2407,7 @@ 2.6.3.10. getMembersCHILDREN_CARDINALITY |
DBTYPE_UI4 |
- |
+ |
The number of children that the member has. This
can be an estimate, so consumers should not rely on
this to be the exact count. Providers should return
@@ -2389,7 +2416,7 @@ | 2.6.3.10. getMembersPARENT_LEVEL |
DBTYPE_UI4 |
- |
+ |
The distance of the member's parent from the
root level of the hierarchy. The root level is zero
(0). |
@@ -2397,69 +2424,73 @@ 2.6.3.10. getMembersPARENT_UNIQUE_NAME |
DBTYPE_WSTR |
- |
+ |
The unique name of the member's parent. NULL
is returned for any members at the root level. |
PARENT_COUNT |
DBTYPE_UI4 |
- |
+ |
The number of parents that this member has. |
DESCRIPTION |
DBTYPE_WSTR |
- |
+ |
Always returns NULL. |
EXPRESSION |
DBTYPE_WSTR |
- |
+ |
The expression for calculations, if the member
is of type MDMEMBER_TYPE_FORMULA. |
MEMBER_KEY |
DBTYPE_WSTR |
- |
+ |
The value of the member's key column. Returns
NULL if the member has a composite key. |
IS_PLACEHOLDERMEMBER |
DBTYPE_BOOL |
- |
+ |
A Boolean that indicates whether a member is a
placeholder member for an empty position in a
dimension hierarchy. |
+
It is valid only if the MDX Compatibility property has been set to 1. - IS_DATAMEMBER |
DBTYPE_BOOL |
- |
+ |
A Boolean that indicates whether the member is a
- data member. |
+ data member.
+
+ Returns True if the member is a data - member. Returns True if the member is a data + member. Zero or more additional columns |
DBTYPE_UI2 |
- |
+ |
No properties are returned if the members could
be returned from multiple levels. For example, if
the Tree operator is PARENT and SELF
for a non-parent child hierarchy, no member
- properties are returned. |
+ requested).
This applies to ragged + properties are returned. + + This applies to ragged hierarchies where tree operators could return members from different levels (for example, if the prior level contains holes and parent on members is - requested). |
The rowset is sorted on CATALOG_NAME, SCHEMA_NAME, CUBE_NAME, DIMENSION_UNIQUE_NAME, @@ -2473,7 +2504,7 @@
2.6.3.11. getProperties
The returned result set contains the following columns.
| Column name | Type indicator | Description | @@ -2576,32 +2607,39 @@CHARACTER_MAXIMUM_LENGTH | DBTYPE_UI4 | The maximum possible length of the property, if
- it is a character, binary, or bit type. Zero - indicates there is no defined maximum length. -Returns NULL for all other data types. |
+ it is a character, binary, or bit type.
+
+
|---|---|---|---|---|---|
| CHARACTER_OCTET_LENGTH | DBTYPE_UI4 | The maximum possible length (in bytes) of the
- property, if it is a character or binary type. - Zero indicates there is no defined maximum length. -Returns NULL for all other data types. |
+ property, if it is a character or binary type.
+
+ |||
| NUMERIC_PRECISION | DBTYPE_UI2 | The maximum precision of the property, if it is
- a numeric data type. Returns NULL for all - other data types. |
+ a numeric data type.
+
+ |||
| NUMERIC_SCALE | DBTYPE_I2 | The number of digits to the right of the decimal
point, if it is a DBTYPE_NUMERIC or
- DBTYPE_DECIMAL type. Returns NULL for - all other data types. |
+ DBTYPE_DECIMAL type.
+
+ |||
| DESCRIPTION | @@ -2735,10 +2773,12 @@PROPERTY_IS_VISIBLE | DBTYPE_BOOL | A Boolean that indicates whether the property is
- visible. TRUE if the property is visible; - otherwise, FALSE. |
+ visible.
+
+
This schema rowset is not sorted.
@@ -2749,7 +2789,7 @@2.6.3.12. getSets
The returned result set contains the following columns.
| Column name | Type indicator | Description | @@ -2815,17 +2855,15 @@
|---|
The rowset is sorted on CATALOG_NAME, SCHEMA_NAME, CUBE_NAME.
--
2.6.4. Other methods
| Method | Description | getMdxKeywords() |
Returns | -
|---|
OlapDatabaseMetaData extends
Classes:
@@ -2856,7 +2894,6 @@2.6.4. Other methods
2.7. Transform
@@ -2868,7 +2905,7 @@2.7. Transform
SELECT {[Measures].[Store Sales], [Measures].[Unit Sales]} ON COLUMNS,- {[Product].Members} ON ROWS
+ {[Product].Members} ON ROWS
FROM [Sales] @@ -2877,13 +2914,136 @@
2.7. Transform
- Order({[Product].Members}, [Measures].[Unit Sales], ASC) ON ROWS
+ Order({[Product].Members}, [Measures].[Unit Sales], ASC) ON ROWS
FROM [Sales]
Transformations can only modify a query within a cube - it cannot be used to +change the cube that the query is against or to join two cubes. Similarly, the +transform package only supports modifying a MDX query model. For example, a +"drill" transform can not be used to produce a SQL query that returns data +outside of the cube.
+Package name: org.olap4j.transform
-Classes: TBD
+Classes: (incomplete)
+-
+
- Tuple +
- Set +
- CalculatedMember +
- NamedSet +
- Axis +
- Slicer +
2.7.1. Query Model Details
+This section should probably be moved into Section 2.4
+ +The MDX query language uses a data model based on cubes, dimensions, tuples +and sets. The transformation package allows direct manipulation of a query +exploring a cube.
+ +A tuple is a multidimensional member. It is a combination of members from one +or more dimensions, with the limitation that only one member can be used from each +dimension. A set is an ordered collection of tuples. An MDX query selects +zero or more axes using a data slicer. (The axes loosely correspond to the "SELECT" +clause in a SQL query, and the slicer to the "WHERE".) + +
2.7.2. Navigation Actions
+ +The defined set of navigations can be divided into four categories: Slicing, +Restructuring, Drilling, Scoping.
+ +2.7.2.1. Slicing Navigations
+-
+
- setSlicer
- Secifies the slicer to use, replacing any current one. +
- getSlicer
- Retrieve the current slicer. +
- excludeEmpty
- Removes empty slices from the results. +
- setLimit
- Limits the results to the top/bottom n results + for a specified measure. +
2.7.2.2. Restructuring Navigations
+Restructuring navigations change the axes of the returned cube.
+ +-
+
- getAxis +
- setAxis
- Specifies the Set to use for an Axis. Can be used to add or + replace a axis. +
- deleteAxis
- Removes the specified Axis from the results. +
- addToAxis
- Appends a new Tuple or Set to an Axis. +
- moveTuple
- Moves a tuple from one Axis to another. If the tuple + is not contained in the first axis this method behaves like addToAxis on + the second axis. +
- reorderAxis
- Reorders the tuples in the axis. +
- addTotal
- Adds an aggregation (total, min, max, count, distinct) + to the specified member. More than one aggregation can be added to a single + member. +
- deleteTotal
- Deletes an aggregation from the specified member. +
2.7.2.3. Drilling Navigations
+Navigations that allow a user to move through the levels in a hierarchy. All +drill navigations operate on a single Axis.
+-
+
- drill
- Moves the specified member up/down one level in the + hierarchy. All members of the hierarchy are replaced by this action. +
2.7.2.4. Scoping Navigations
+Navigations that allow a user to expand/collapse sections of a result set. +All scoping navigations operate on single Axis.
+-
+
- expand
- Expand the given measure to include both the current + level and all the members one level down + the hierarchy. Optionally expands a single measure or all measures at the + level. +
- collapse
- Removes members at a given level of a hierarchy. + Optionally collapses a single measure or all measures at the level. + +
2.7.2.5. Supporting Actions
+Axis Operations
+-
+
- getSet +
- setSet +
- addToAxis +
- removeFromAxis +
Set Operations
+-
+
- getTuple +
- setTuple +
- addToSet - includes Tuples, ranges of Tuples, functions, properties +
- removeFromSet +
Tuple Operations
+-
+
- addMember +
- deleteMember +
- getMembers +
Open Issues
+-
+
- Is this API at the right level, or is it too close to MDX? +
- Do we want to include support for adding highlighting conditions? +
- What about result formatting as part of the query? +
- Should common operators such as CrossJoin(), Order() and Filter() + be baked into the API as methods, or just treated as functions? +
- How should we handle functions that return or modify Sets? We want to + make it easy to wrap an entire axis in a function. +
- Should we limit the Slicer to a Tuple or allow a Set? I believe the MDX + spec allows a Set, but I don't know if anybody supports it. +
- I think we should add some explicit time based functions, since time + based analysis is so common, and so frequently done wrong. ie if the Axis + is using a time based dimension you can use "setCompareToPreviousTimePeriod()" + instead of having to add the previous time period as a member and calculate + the change. +
2.8. Layout
@@ -2982,15 +3142,15 @@Appendix B. Feedback
Richard Emberson, email, 2006/8/15
-"One thing we found about XMLA was that our users wanted all roles to be -defined, stored, modified, and accessed though the same mechanism. With a large -application with many areas that can be permissioned, it is important that -olap4j let an application builder manage roles externally and apply them as part -of an individual's execution context."
+"One thing we found about XMLA was that our users wanted all roles to be +defined, stored, modified, and accessed though the same mechanism. With a large +application with many areas that can be permissioned, it is important that +olap4j let an application builder manage roles externally and apply them as part +of an individual's execution context."
Appendix C. Open issues
-These issues will be voted upon at the next meeting. If they are accepted, +
These issues will be voted upon at the next meeting. If they are accepted, they will generally be put into the spec.
(No issues are currently open.)
@@ -3006,7 +3166,7 @@D.2. Design notes
JDK. We are targeting JDK 1.5, and running retroweaver for backward compatibility for JDK 1.4. See forum thread: - + olap4j, JDK 1.5 and generics.
Appendix E. References
@@ -3014,8 +3174,6 @@Appendix E. References
1. XMLA: XML for Analysis Specification, version 1.1
-- - +
- \ No newline at end of file +