Facts and figures

Are there any facts and figures available that shows the difference between ROLAP and MOLAP storage options.
I want to know the facts and figures specially in context of
Data Loading Time
Data retrieval Time
Partioning Creation Time
Cube Maitenance Time

Naughty naughty General - they dont do "daft" on this forum, you should know that.
"You may well think that, I'm afraid I could'nt possibly comment"
Francis Urqhuart, who was never known by his initials to his friends.
AQ.
"Welcome to Royston Vasey - You'll never leave."

Similar Messages

Facts and Figures - A Question for the Forum Mods

A bit of a daft question for which I am sure the Forum Mods can provide an answer.
How many folks were registered on the old forum and how many on the new one?
I just want to put something BT Chairman Sir Michael Rake wrote to BT shareholders this month into context.
"To forbid us anything is to make us have a mind for it."
-- Michel de Montaigne, Essays, 1559

Naughty naughty General - they dont do "daft" on this forum, you should know that.
"You may well think that, I'm afraid I could'nt possibly comment"
Francis Urqhuart, who was never known by his initials to his friends.
AQ.
"Welcome to Royston Vasey - You'll never leave."

Delete Fact and Dimension Tables

Hai All,
Small question! When deleting data from info cube, it asks whether to delete just Dimension table or both fact and Dimension tables.
What is the difference between these two?
Thank you.

Hi Visu,
The dimension table will contain the references to char value by way of SID and DIM ids, whereas the fact table will contain the number (of key figures). If you delete just the Fact table, the numbers go away, yet the DIM ids remain intact, so reload is faster. But if you are convinced that this data is not correct either, or you want a clean slate to strat reload again, then delete both Fact and Dim tables. Then when you reload, the DIM ids will be created again.
Hope this helps...

Fact and dimension table partition

My team is implementing new data-warehouse. I would like to know that when should we plan to do partition of fact and dimension table, before data comes in or after?

Hi,
It is recommended to partition Fact table (Where we will have huge data). Automate the partition so that each day it will create a new partition to hold latest data (Split the previous partition into 2). Best practice is to create partition on transaction
timestamps so load the incremental data into a empty table called (Table_IN) and then Switch that data into main table (Table). Make sure your tables (Table and Table_IN) should be on one file group.
Refer below content for detailed info
Designing and Administrating Partitions in SQL Server 2012
A popular method of better managing large and active tables and indexes is the use of partitioning. Partitioning is a feature for segregating I/O workload within
SQL Server database so that I/O can be better balanced against available I/O subsystems while providing better user response time, lower I/O latency, and faster backups and recovery. By partitioning tables and indexes across multiple filegroups, data retrieval
and management is much quicker because only subsets of the data are used, meanwhile ensuring that the integrity of the database as a whole remains intact.
Tip
Partitioning is typically used for administrative or certain I/O performance scenarios. However, partitioning can also speed up some queries by enabling
lock escalation to a single partition, rather than to an entire table. You must allow lock escalation to move up to the partition level by setting it with either the Lock Escalation option of Database Options page in SSMS or by using the LOCK_ESCALATION option
of the ALTER TABLE statement.
After a table or index is partitioned, data is stored horizontally across multiple filegroups, so groups of data are mapped to individual partitions. Typical
scenarios for partitioning include large tables that become very difficult to manage, tables that are suffering performance degradation because of excessive I/O or blocking locks, table-centric maintenance processes that exceed the available time for maintenance,
and moving historical data from the active portion of a table to a partition with less activity.
Partitioning tables and indexes warrants a bit of planning before putting them into production. The usual approach to partitioning a table or index follows these
steps:
1. Create
the filegroup(s) and file(s) used to hold the partitions defined by the partitioning scheme.
2. Create
a partition function to map the rows of the table or index to specific partitions based on the values in a specified column. A very common partitioning function is based on the creation date of the record.
3. Create
a partitioning scheme to map the partitions of the partitioned table to the specified filegroup(s) and, thereby, to specific locations on the Windows file system.
4. Create
the table or index (or ALTER an existing table or index) by specifying the partition scheme as the storage location for the partitioned object.
Although Transact-SQL commands are available to perform every step described earlier, the Create Partition Wizard makes the entire process quick and easy through
an intuitive point-and-click interface. The next section provides an overview of using the Create Partition Wizard in SQL Server 2012, and an example later in this section shows the Transact-SQL commands.
Leveraging the Create Partition Wizard to Create Table and Index Partitions
The Create Partition Wizard can be used to divide data in large tables across multiple filegroups to increase performance and can be invoked by right-clicking
any table or index, selecting Storage, and then selecting Create Partition. The first step is to identify which columns to partition by reviewing all the columns available in the Available Partitioning Columns section located on the Select a Partitioning Column
dialog box, as displayed in Figure 3.13. This screen also includes additional options such as the following:
Figure 3.13. Selecting a partitioning column.
The next screen is called Select a Partition Function. This page is used for specifying the partition function where the data will be partitioned. The options
include using an existing partition or creating a new partition. The subsequent page is called New Partition Scheme. Here a DBA will conduct a mapping of the rows selected of tables being partitioned to a desired filegroup. Either a new partition scheme should
be used or a new one needs to be created. The final screen is used for doing the actual mapping. On the Map Partitions page, specify the partitions to be used for each partition and then enter a range for the values of the partitions. The
ranges and settings on the grid include the following:
Note
By opening the Set Boundary Values dialog box, a DBA can set boundary values based on dates (for example, partition everything in a column after a specific
date). The data types are based on dates.
Designing table and index partitions is a DBA task that typically requires a joint effort with the database development team. The DBA must have a strong understanding
of the database, tables, and columns to make the correct choices for partitioning. For more information on partitioning, review Books Online.
Enhancements to Partitioning in SQL Server 2012
SQL Server 2012 now supports as many as 15,000 partitions. When using more than 1,000 partitions, Microsoft recommends that the instance of SQL Server have at
least 16Gb of available memory. This recommendation particularly applies to partitioned indexes, especially those that are not aligned with the base table or with the clustered index of the table. Other Data Manipulation Language statements (DML) and Data
Definition Language statements (DDL) may also run short of memory when processing on a large number of partitions.
Certain DBCC commands may take longer to execute when processing a large number of partitions. On the other hand, a few DBCC commands can be scoped to the partition
level and, if so, can be used to perform their function on a subset of data in the partitioned table.
Queries may also benefit from a new query engine enhancement called partition elimination. SQL Server uses partition enhancement automatically if it is available.
Here’s how it works. Assume a table has four partitions, with all the data for customers whose names begin with R, S, or T in the third partition. If a query’s WHERE clause
filters on customer name looking for ‘System%’, the query engine knows that it needs only to partition three to answer
the request. Thus, it might greatly reduce I/O for that query. On the other hand, some queries might take longer if there are more than 1,000 partitions and the query is not able to perform partition elimination.
Finally, SQL Server 2012 introduces some changes and improvements to the algorithms used to calculate partitioned index statistics. Primarily, SQL Server 2012
samples rows in a partitioned index when it is created or rebuilt, rather than scanning all available rows. This may sometimes result in somewhat different query behavior compared to the same queries running on SQL Server 2012.
Administrating Data Using Partition Switching
Partitioning is useful to access and manage a subset of data while losing none of the integrity of the entire data set. There is one limitation, though. When
a partition is created on an existing table, new data is added to a specific partition or to the default partition if none is specified. That means the default partition might grow unwieldy if it is left unmanaged. (This concept is similar to how a clustered
index needs to be rebuilt from time to time to reestablish its fill factor setting.)
Switching partitions is a fast operation because no physical movement of data takes place. Instead, only the metadata pointers to the physical data are altered.
You can alter partitions using SQL Server Management Studio or with the ALTER TABLE...SWITCH
Transact-SQL statement. Both options enable you to ensure partitions are
well maintained. For example, you can transfer subsets of data between partitions, move tables between partitions, or combine partitions together. Because the ALTER TABLE...SWITCH statement
does not actually move the data, a few prerequisites must be in place:
• Partitions must use the same column when switching between two partitions.
• The source and target table must exist prior to the switch and must be on the same filegroup, along with their corresponding indexes,
index partitions, and indexed view partitions.
• The target partition must exist prior to the switch, and it must be empty, whether adding a table to an existing partitioned table
or moving a partition from one table to another. The same holds true when moving a partitioned table to a nonpartitioned table structure.
• The source and target tables must have the same columns in identical order with the same names, data types, and data type attributes
(length, precision, scale, and nullability). Computed columns must have identical syntax, as well as primary key constraints. The tables must also have the same settings for ANSI_NULLS and QUOTED_IDENTIFIER properties.
Clustered and nonclustered indexes must be identical. ROWGUID properties
and XML schemas must match. Finally, settings for in-row data storage must also be the same.
• The source and target tables must have matching nullability on the partitioning column. Although both NULL and NOT
NULL are supported, NOT
NULL is strongly recommended.
Likewise, the ALTER TABLE...SWITCH statement
will not work under certain circumstances:
• Full-text indexes, XML indexes, and old-fashioned SQL Server rules are not allowed (though CHECK constraints
are allowed).
• Tables in a merge replication scheme are not allowed. Tables in a transactional replication scheme are allowed with special caveats.
Triggers are allowed on tables but must not fire during the switch.
• Indexes on the source and target table must reside on the same partition as the tables themselves.
• Indexed views make partition switching difficult and have a lot of extra rules about how and when they can be switched. Refer to
the SQL Server Books Online if you want to perform partition switching on tables containing indexed views.
• Referential integrity can impact the use of partition switching. First, foreign keys on other tables cannot reference the source
table. If the source table holds the primary key, it cannot have a primary or foreign key relationship with the target table. If the target table holds the foreign key, it cannot have a primary or foreign key relationship with the source table.
In summary, simple tables can easily accommodate partition switching. The more complexity a source or target table exhibits, the more likely that careful planning
and extra work will be required to even make partition switching possible, let alone efficient.
Here’s an example where we create a partitioned table using a previously created partition scheme, called Date_Range_PartScheme1.
We then create a new, nonpartitioned table identical to the partitioned table residing on the same filegroup. We finish up switching the data from the partitioned table into the nonpartitioned table:
CREATE TABLE TransactionHistory_Partn1 (Xn_Hst_ID int, Xn_Type char(10)) ON Date_Range_PartScheme1 (Xn_Hst_ID) ; GO CREATE TABLE TransactionHistory_No_Partn (Xn_Hst_ID int, Xn_Type
char(10)) ON main_filegroup ; GO ALTER TABLE TransactionHistory_Partn1 SWITCH partition1 TO TransactionHistory_No_Partn; GO
The next section shows how to use a more sophisticated, but very popular, approach to partition switching called a sliding
window partition.
Example and Best Practices for Managing Sliding Window Partitions
Assume that our AdventureWorks business is booming. The sales staff, and by extension the AdventureWorks2012 database, is very busy. We noticed over time that
the TransactionHistory table is very active as sales transactions are first entered and are still very active over their first month in the database. But the older the transactions are, the less activity they see. Consequently, we’d like to automatically group
transactions into four partitions per year, basically containing one quarter of the year’s data each, in a rolling partitioning. Any transaction older than one year will be purged or archived.
The answer to a scenario like the preceding one is called a sliding window partition because
we are constantly loading new data in and sliding old data over, eventually to be purged or archived. Before you begin, you must choose either a LEFT partition function window or a RIGHT partition function window:
1. How
data is handled varies according to the choice of LEFT or RIGHT partition function window:
• With a LEFT strategy, partition1 holds the oldest data (Q4 data), partition2 holds data that is 6- to 9-months old (Q3), partition3
holds data that is 3- to 6-months old (Q2), and partition4 holds recent data less than 3-months old.
• With a RIGHT strategy, partition4 holds the holds data (Q4), partition3 holds Q3 data, partition2 holds Q2 data, and partition1
holds recent data.
• Following the best practice, make sure there are empty partitions on both the leading edge (partition0) and trailing edge (partition5)
of the partition.
• RIGHT range functions usually make more sense to most people because it is natural for most people to to start ranges at their lowest
value and work upward from there.
2. Assuming
that a RIGHT partition function windows is used, we first use the SPLIT subclause of the ALTER PARTITION FUNCTIONstatement
to split empty partition5 into two empty partitions, 5 and 6.
3. We
use the SWITCH subclause
of ALTER TABLE to
switch out partition4 to a staging table for archiving or simply to drop and purge the data. Partition4 is now empty.
4. We
can then use MERGE to
combine the empty partitions 4 and 5, so that we’re back to the same number of partitions as when we started. This way, partition3 becomes the new partition4, partition2 becomes the new partition3, and partition1 becomes the new partition2.
5. We
can use SWITCH to
push the new quarter’s data into the spot of partition1.
Tip
Use the $PARTITION system
function to determine where a partition function places values within a range of partitions.
Some best practices to consider for using a slide window partition include the following:
• Load newest data into a heap, and then add indexes after the load is finished. Delete oldest data or, when working with very large
data sets, drop the partition with the oldest data.
• Keep an empty staging partition at the leftmost and rightmost ends of the partition range to ensure that the partitions split when
loading in new data, and merge, after unloading old data, do not cause data movement.
• Do not split or merge a partition already populated with data because this can cause severe locking and explosive log growth.
• Create the load staging table in the same filegroup as the partition you are loading.
• Create the unload staging table in the same filegroup as the partition you are deleting.
• Don’t load a partition until its range boundary is met. For example, don’t create and load a partition meant to hold data that is
one to two months older before the current data has aged one month. Instead, continue to allow the latest partition to accumulate data until the data is ready for a new, full partition.
• Unload one partition at a time.
• The ALTER TABLE...SWITCH statement
issues a schema lock on the entire table. Keep this in mind if regular transactional activity is still going on while a table is being partitioned.
Thanks Shiven:) If Answer is Helpful, Please Vote

In Answers am seeing "Folder is Empty" for Logical Fact and Dimension Table

Hi All,
Am working on OBIEE Answers, on of sudden when i clicked on Logical Fact table it showed me as "folder is empty". I restarted all the services and then tried still showing same for Logical Fact and Dimension tables but am able to see all my reports in Shared Folders. I restarted the machine too but no change. Please help me out to resolve this issue.
Thanks in Advance.
Regards,
Rajkumar.

First of all, follow the forum etiquette :
http://forums.oracle.com/forums/ann.jspa?annID=939
React or mark as anwser the post that the user gave.
And for your question, you must check the log for a possible corrupt catalog :
OracleBIData_Home\web\log\sawlog0.log

Best practice when FACT and DIMENSION table are the same

Hi,
In my physical model I have some tables that are both fact and dimension table, i.e. in the BMM they are of course separated into Fact and Dim source (2 different units) and it works fine. But I can see that there will be trouble when having more fact tables and I e.g. have a Period dimension pointing to all the different fact tables (different sources).
Seems like the best solution to this is to have an alias of the fact/transaction table and have 2 "copies" of the transaction table (one for fact and one for dimension table) in the physical layer. Only bad thing is that there will then allways be 2 lookups in the same table when fetching data from the dimension and the fact table.
This is not built on a datawarehouse - so the architecture is thereby more complex. Hope this was understandable (trying to make a short story of it).
Any best practice on this? Or other suggestions.

Id recommend creation of a view in the database. if its an oracle DB, materialised views would be a huge performance benefit. you just need to make sure that the MVs are updated when the source is updated.
-Domnic

How to design fact and dimension tables

Hi Team,
Please provide me some useful links!!
I have a Parent & Child table each has around 8 Million records (1 to many relation). These two tables need relation with many other master tables to generate any report.
I want to desing a fact and dimension(s) for this parent & Child tables.
Please help me what are the things I have to keep in mind when desingning datawarehouse fact and dimension tables?
Thanks,
Ali

Hi, any update on this?

Best Practice - Outer Join between Fact and Dim table

Hi Gurus,
Need some advice on the below scenario
I have an OOTB subject area and we have around 50-60 reports based on it. The related subject area Fact and Dim1 table are having inner join.
Now I have a scenario for one report where outer join has to be implemented between Fact and Dim1. Here I am against changing the OOTB subject area join as the outer join will impact the performance of other 50-60 reports.
Can anyone provide any inputs on what is the best way to handle this scenario?
Thanks

Ok. I tried this:
Driving table : Fact, Left outer join -- didnt work.
Driving table: Dimension D left outer join -- didnt work either
In either the case, I see physical query as D left outer Join on Fact F. and omitting the rows.
And then I tried this -
Driving table: Fact, RIght outer join.
Now, this is giving me error:
Sybase][ODBC Driver]Internal Error. [nQSError: 16001] ODBC error state: 00000 code: 30128 message: [Sybase][ODBC Driver]Data overflow. Increase specified column size or buffer size. [nQSError: 16011] ODBC error occurred while executing SQLExtendedFetch to retrieve the results of a SQL statement. (HY000)
I checked all columns, everything matched with database table type and size.
I am pulling Fact.account number, Dimension.account name, Fact.Measures. I am seeing this error each time I pull Fact.Account number.

Unable to Create Fact and Dimension tables from the Tools menu in EIS conso

Hi All,
In the EIS console, I am unable to create the fact table and the dimension tables to produce my OLAP model from the TOOLS menu whereas I am able to create them by dragging from the left panel where the tables are displayed. I am geeting the below error message:
"An exception occured while retrieving OLAP model metadata. Please verify you are connected to the catalog and try again"
Any help appreciated.
Thanks,
Raja

I have fact and dimension tables in one server and i moved those stuff to another server.If I do that what happen to essbase and about totale EPM System.I want to know how to do this and what I can expect?
Please reply

How to have fact and dimension which are not joined in same report

Hi All,
suppose we have 2 dimensions and 1 of them is joined to fact but we want to pull both these dimensions along with fact and fact column shows null but we dont want that .how can we have 2nd dimension which is not joined to fact in the same report .Actually i have a column called equipment schedueled time and it can be shown only with equipment dimension but I want to pull both equipment,geography and equipment scheduled time in report if I do it now it shows equipment scheduled time as null because its not joined with geography dimension.I want even if the geography dimension exists it should show the value of equipment scheduled time .
Can someone please help me.
Thanks in Advance

Hi ,
Can you please tell me what are fact and dimension tables of your requirement.If you want display the data from 2 dims and a fact table ,you have to establish the joins between facts and dimensions.
mark if helpful/correct...
thanks,
prassu

Check 2 tables(Table A and Table B) and figure out new columns present in Table A and add these new columns to Table B

How to check 2 tables(Table A and Table B) and figure out new columns present in Table A and add these new columns to Table b.
DDL-
Create table A
( A INT,
B INT,C VARCHAR(2)
Create table B
A INT,
B INT
Any advice on the best approach or method to achieve this.
I understand that I need to check the schema of the columns and then do a match between 2 tables and find new columns and then alter my target table
Mudassar

Can you try this..
CREATE TABLE A ( A INT, B INT, C VARCHAR(2) )
CREATE TABLE B ( A INT, B INT )
Declare @ColumnVar nvarchar(128),@DatatypeVar nvarchar(128)
SELECT @ColumnVar=x.COLUMN_NAME, @DatatypeVar=x.DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS AS x
WHERE TABLE_NAME = 'A'
AND NOT EXISTS ( SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'B'
AND COLUMN_NAME = x.COLUMN_NAME )
Declare @SQL VarChar(1000)
SELECT @SQL = 'ALTER TABLE B ADD ' + @ColumnVar + ' '+ @DatatypeVar
Exec (@SQL)
select * from B
Please Mark This As Answer if it helps to solve the issue
http://stackoverflow.com/questions/2614101/alter-table-my-table-add-column-int

Need to pull the information from two facts and associated dimensions

HI All, i need to pull all the columns from the two Facts and their associated dimensions, get the results.
here is the example:
Fact1 --> D1, D2, D3
FACT2--> DA, DB, DC, D1
D1 Dimension has a Join with two fact tables, as long as i'm using columns from D1 and FACT2, DA, DB, DC report works.
but my requirement is to get the results when pulling the columns from all the dimensions and two facts like Fact1, FACT2, D1, D2, D3, DA, DB, DC
how to achieve this requirement, can someone pls help me with this.
your responses are much appreciated.
Thanks
rar

Hi RAR,
I assume you have created proper dimensional hierarchies for all the dimensions in your subject area. Also, ensure that all of them have a Total Level created.
Assuming the above, since D1 is a conformed dimension, if you create a report having columns from only D1,Fact1 and Fact2, the report should show you proper results.
For creating a report having columns from all tables, ensure the following:
1. For all measure columns from Fact1 to be included in the report, set them to be calculated at the Total Level of dimensions DA, DB and DC
2. For all measure columns from Fact2 to be included in the report, set them to be calculated at the Total Level of dimensions D2 and D3
The physical sql will fire separate queries for the 2 star schemas and then join them using the conformed dimension.
Hope this helps,
Gaurav

Urgent - How to join multiple facts and dimensions in OBIEE rpd??

Hi,
In my RPD I have 3 facts and 4 dimensions and the joins defined are as below
Physical layer - All joins are FK and inner (1:N)
FACTA-------------- DIM_TIME, DIM_CUST,DIM_CAL
FACTB-------------- DIM_TIME, DIM_CUST,DIM_CAL
FACTC-------------- DIM_TIME, DIM_CUST,DIM_CAL, DIM_XYZ
BM layer - All joins are complex, inner
The logical table F1 pulls columns from FACTA, FACTB and FACTC . Complex join exists between all 4 dimensions DIM_TIME, DIM_CUST,DIM_CAL, DIM_XYZ to logical table F1.
Issue: I need to build a report with $ column from FACTA, FACTB and FACTC and need to add filter conditions using columns from DIM_TIME, DIM_CUST,DIM_CAL, DIM_XYZ.
However when ever I add a filter condition from DIM_XYZ the physical query generated is not generating code to access data from FACTA and FACTB. Instead it is subsituting a NULL and just pulls data frm FACTC.
My Questions: What is the best way to build the physical and BMM layer using FACTA, FACTB,FACTC, DIM_TIME, DIM_CUST,DIM_CAL and DIM_XYZ??
I need to resolve this issue ASAP so any help is appreciated. Thanks
Edited by: user11935561 on Feb 10, 2010 6:27 AM
Edited by: user11935561 on Feb 10, 2010 6:28 AM

You can find the same issue in
Logic of queries in OBIEE
or
Connection between 2 fact tables
Follow the link
http://there-n-back-again.blogspot.com/2009/04/oracle-analytics-how-to-report-over-non.html
Put 'All' or 'Total' at levels for dim_xxx for those facts you need in your report from facta and factb
Regards
Nicolae

Adding Tags in PDF for Tables and Figures

Please let me know how to add tags for Table and Figure in the PDF and also about setting up attributes for that

You can add tags to a PDF Document. If the PDF is untagged you can use the advanced, accessabilty, add tags to the document. If the PDF is already tagged or after you have run the add tags you can use the "touch up reading order" menu and then make the item you want to be a table a table etc....
Be Well

Cross-references (MS-Word to WebHelp) not showing up for Tables and Figures

I am converting an MS-Word 2010 document to WebHelp using RH9. Cross-references to numbered sections, appendixes, websites, etc. come out fine. Cross-references to tables and figures do not always appear. In some sections they are there, and in some they are not.
Would anyone be able to offer any insight into how I can get these table and figure cross-references to come out on a regular basis in the WebHelp version? Thank you.

UPDATE TO PREVIOUS MESSAGE: Cross-references to tables and figures NEVER appear in the RH version when coming from MS-Word.
Is there any way to have these cross-references appear? If not, it appears the only solution is to bookmark tables and figures individually and hyperlink to each of them.
Thanks for any help you can offer.
nankinnankin

Facts and figures

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