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| | n The fact table and the relevant dimension tables of an InfoCube are connected with one another relationally using the dimension |
 | | The dimensions are connected to the fact table with the Dim id’s, the access to the data in the fact table takes place using the selection of characteristics and/or their characteristic values from the dimension tables and the generation of the corresponding fact table. | | | The central intersection entities ie many to many relationship between the strong entities are translated as fact table, a record of the fact table is uniquely defined by the keys of the dimension table, a fact table is maintained during transaction data loading. | | | Dimension tables are grouping of related tables, a dimension table consists of generated primary key and characteristics, the keys of the dimensions are foreign keys in the fact table. |
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http://www.bridgeport.edu/sed/projects/cs597/Spring_2004/kyarlag/infocube.htm
(556 words)
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| | DBMS - September 1998 - Data Warehouse Architect |
| | If you are descending the tree from certain selected parents to various subsidiaries, you join the dimension table to the helper table and the helper table to the fact table with the joins as shown in Figure 3. | | | Instead of using a recursive pointer, you can solve this modeling problem by inserting a helper table between the dimension table and the fact table, as shown in Figure 3. | | | The solution to last month's problem was to create a special helper table between the fact table and the dimension table. |
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http://www.dbmsmag.com/9809d05.html
(1803 words)
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| | stars.doc |
| | Remember that if a majority of the fact table needs to be included, the best thing is usually a table scan, which is no longer a bad thing if you are using parallel query (which you should be if you have a data warehouse). | | | Drilling to Another Fact Table As a matter of fact (no pun intended!), it's important that a dimension table used by one fact table can be shared by other fact tables that need them to facilitate drilling across the dimension to get access to data in the other fact table. | | | The problem with this is that if you have very large dimension tables, or many rows in the fact table that don't match any dimensions, then this cartesian product strategy can actually cause worse performance than if traditional optimization is used. |
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http://cis.bentley.edu/mrobbert/CS753/stars.doc
(3125 words)
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| | Data Warehouse Design Considerations for SQL Server 2000 |
| | Partitioned fact tables can be viewed as one table with an SQL UNION query as long as the number of tables involved does not exceed the limit for a single query. | | | Physical design considerations, such as fact table partitioning, load performance, and query performance, may indicate a different structure for the fact table primary key than the composite key that is in the logical model. | | | The date and time dimensions are created and maintained in the data warehouse independent of the other dimension tables or fact tables – updating date and time dimensions may involve only a simple annual task to mechanically add the records for the next year. |
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http://www.microsoft.com/technet/prodtechnol/sql/2000/reskit/part5/c1761.mspx
(9842 words)
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| | Dimensional Model Standards |
| | Dimension tables that are referenced or are likely to be referenced by multiple fact tables are "conformed dimensions." If conformed dimensions already exist for any of the dimensions in your model, you will be expected to use the conformed versions. | | | Explanations of any "factless fact tables." (A "factless fact table" may be used to count occurrences of an event where no information is needed except the count itself. | | | Note: Aggregation tables are either (a) transparent to the user, such that all SQL is written to go against the lowest level of granularity, or (b) explicit--i.e., seen and queried by the user. |
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http://www.cms.hhs.gov/it/database/das/StarModl.asp
(2215 words)
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| | DBMS - June 1998 - Data Warehouse Architect |
| | In this case, the surrogate key in the fact table is a foreign key, which means that the value of the surrogate key exists in the corresponding dimension table. | | | Fact tables with four and 12 foreign keys connecting outward to a halo of dimension tables present an interesting challenge during data extraction: You must intercept all the incoming fact records and replace all their key components with the correct surrogate key values at high speed. | | | Dimension processing logic for all refreshes of a dimension table after the original load. |
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http://members.fortunecity.com/rhubarb404/orahtml/dbmsmag/9806d05.html
(1996 words)
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| | DBMS - August 1998 - Data Warehouse Architect |
| | Although the helper table clearly violates the classic star join design where all the dimension tables have a simple one-to-many relationship to the fact table, there is no avoiding the issue of what to do with multivalued dimensions that designers insist on attaching to a fact table. | | | Put a helper table in between this fact table and the Diagnosis dimension table. | | | The helper table in the middle is the Diagnosis Group table. |
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http://www.fortunecity.com/skyscraper/oracle/699/orahtml/dbmsmag/9808d05.html
(1979 words)
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| | tipfeb05.html |
| | When one dimension grows very large in relation to the fact table, it makes it difficult for the database optimizer to choose an efficient path to the data, because the guideline of each dimension having less than 10 percent of the fact table’s records has been violated. | | | The goal is that each dimension is of approximately equal size and that the file size of each dimension does not make up more than 10 percent of the associated fact table. | | | A dimension that is very large in relation to a fact table should be a red flag. |
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http://www.sapinsideronline.com/spijsp/insiderBWTips/feb05/tipfeb05.html
(1242 words)
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| | DBMS - October 1995 - Data Warehouse Architect |
| | The central table is called the fact table, and it is the largest table in the schema. | | | Multitable join queries occur after a series of browses and involve constraints placed on several of the dimension tables that are all joined to the fact table simultaneously. | | | The fields in dimension tables are typically textual and are used as the source of constraints and row headers in reports. |
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http://www.dbmsmag.com/9510d05.html
(1613 words)
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| | SQL Server Professional: October 2000 - The Star Schema: Your Data Warehouse's Foundation |
| | Dimension tables are also often "short." You might have many products, but even so, the dimension table won't come close to matching the size of a fact table. | | | In most fact tables all of the fields are numeric, which can require less storage space than the long descriptions you find in the dimension tables. | | | Given that a dimension table is fat, it might be temptingespecially for veteran DBAsto denormalize the dimension table. |
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http://www.ciobriefings.com/WhitePapers/SQLPro/StarSchema.htm
(2393 words)
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| | I have a small problem relating to the relationships that exist between a dimension table and a fact table. |
| | I have a small problem relating to the relationships that exist between a dimension table and a fact table. | | | You can even create a view that joins the two dimension tables to fool the BI tool's semantic layer into thinking that a particular fact is linked to the parent Customer Master dimension. | | | In other words, the query tool or user must be smart enough to include time references for both the fact and associated dimensions in the query an not rely exclusively on the keys. |
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http://www.dmreview.com/article_sub.cfm?articleId=6349
(2060 words)
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| | Re: SSIS: Inserting unknown members from fact table - MSDN |
| | Looking up surrogate keys in a dimension table and adding these to your data flow is easy when there is a match in your dimension table for every key in your fact table. | | | This cannot be done with the described approach, since all unknown business keys in the fact table will be mapped to a single "Unknown" member in the dimension table. | | | It's not easy to fill dimension tables and the fact table from one source in one dataflow when you want to assign surrogate keys in it, too... |
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http://forums.microsoft.com/msdn/ShowPost.aspx?PostID=75211
(2003 words)
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| | Schema Modeling Techniques |
| | After the relevant fact table rows have been retrieved using this access path, they are joined with the dimension tables and temporary tables to produce the answer to the query. | | | Each dimension table is joined to the fact table using a primary key to foreign key join, but the dimension tables are not joined to each other. | | | The optimizer may also decide, based on the properties of the tables and the query, that the transformation does not merit being applied to a particular query. |
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http://www.cs.umb.edu/cs634/ora9idocs/server.920/a96520/schemas.htm
(2553 words)
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| | MIT Data Warehouse: Creating Advanced Queries |
| | The All Data Warehouse Tables page is your reference for identifying which tables are Fact tables and which ones are Dimension tables (see the Type column). | | | The Fact table is the body of the star and the Dimension tables are the points of the star. | | | Dimension tables contain fields that can be used to limit your queries or group numbers in your report. |
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http://www.mit.edu:8001/afs/athena.mit.edu/project/warehouse/aquery.html
(838 words)
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| | Bottom-Up and LR Parsing |
| | One important fact to keep in mind when constructing LR parsing tables is that the state on the top of the stack provides a wealth of information to the parser. | | | Table: An example parse using the parsing table and the LR parsing algorithm. | | | The LR parsing table, as mentioned, is split into the action and goto sections. |
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http://www.csd.uwo.ca/~wozniak/cs447a-fall2001/notes/06_-_bottom-up-LR
(1666 words)
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| | OLAP Setup and User's Guide |
| | Because the dimension tables can be joined to the fact table, the SELECT statements can retrieve values from the fact table based on attribute values that you define, rather than just on the member name. | | | Relational columns cannot be removed from relational tables; after you add one, it remains part of the dimension table as long as the table exists. | | | When you use the data load rules editor, you can add text before (and after) a column of data values from the external data table. |
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http://www.seas.ucla.edu/db2/db2ip/db2ip71.htm
(709 words)
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| | The Main Transposition Table |
| | It's possible that this line of reasoning inspired early computer chess programmers, and this is in fact a minor reason to implement a transposition hash table. | | | Since many positions are apt to map to the same element in the hash table, the table elements contain a verification value, which can be used to make sure that the element in the table is the one that you are trying to find. | | | A transposition hash table can be used to detect these cases in order to avoid duplicating work. |
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http://www.seanet.com/~brucemo/topics/hashing.htm
(1232 words)
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| | Secrets of Oracle9i Database: Table Compression |
| | For this hash-join the fact table is the probe table, which is accessed using rowids obtained in the previous phase. | | | For Query 2 and Query 3 it is the access of the summary table WEEKLY_SALES. | | | Data from a compressed table is read and cached in its compressed format and is decompressed only at data access time. |
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http://www.oracle.com/technology/oramag/webcolumns/2003/techarticles/poess_tablecomp.html
(3066 words)
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| | SparkNotes: Hash Tables: What is a Hash Table? |
| | A hash function doesn't guarantee that every input will map to a different output (in fact, as we'll see in the next section, it shouldn't do this). | | | A hash table is made up of two parts: an array (the actual table where the data to be searched is stored) and a mapping function, known as a hash function. | | | The hash function is a mapping from the input space to the integer space that defines the indices of the array. |
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http://www.sparknotes.com/cs/searching/hashtables/section1.html
(825 words)
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| | File Allocation Table - Wikipedia, the free encyclopedia |
| | Each file or directory stored within it is represented by a 32 byte entry in the table. | | | FAT is used on these drives for reasons of compatibility and size overhead, as well as the fact that file permissions on removable media are likely to be more trouble than they are worth. | | | The FAT file system is considered relatively uncomplicated, and is consequently supported by virtually all existing operating systems for personal computers. |
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http://en.wikipedia.org/wiki/File_Allocation_Table
(5060 words)
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| | Programming Pivot Tables for Access Forms (Smart Access 2003) |
| | Pivot tables derive their name from the fact that they permit analysts to pivot, or drag, variables between row, column, and filter axes. | | | Pivot tables are popular with financial and operational analysts because they serve as a "slicer and dicer" for data. | | | When Access developers offer pivot tables to their clients as an output mode, they empower users to perform many tasks that used to require custom programming with cross-tab queries. |
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http://msdn.microsoft.com/library/en-us/dnsmart03/html/sa03l7.asp?frame=true
(2692 words)
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| | Pivot Table: Excel Pivot Table. Pivot Table Tutorials and Downloads |
| | Perhaps the biggest advantage to using Pivot Tables is the fact that we can generate and extract meaningful information from a large table of information within a matter of minutes. | | | As our Pivot Table will be basing all its data on this list or table it is vital that we set our tables and lists up in a uniform way. | | | This makes Pivot Tables interactive in that once the table is complete we can very easily see what effect moving (or pivoting) our data has on our information. |
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http://www.ozgrid.com/Excel/excel-pivot-tables.htm
(1366 words)
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| | Shared File Systems |
| | The File System finds the information for File1 in the File Allocation Table, and detects that this file has 5 blocks allocated, and file block number 5 is stored in the block number 123456 on the disk. | | | Since the File System running on computer X is not aware of this fact, it will continue to use its cache providing computer X applications with data that is no longer valid. | | | The File System running on that computer will modify its File Allocation Table, but it will have no effect on the File Allocation Tables loaded on other computers. |
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http://www.stalker.com/notes/SFS.html
(2043 words)
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| | Descriptor Tables |
| | Another reason is the fact that the maximum size of a Descriptor Table is limited to 64 KB ( 64 KB (65536) / 8 = 8192 possible, 8 byte long entries = 8192 Descriptors). | | | The consequence is that descriptors may not be defined at a random position in memory, but only within the descriptor table (fig. | | | The other Descriptor Table, the "Interrupt Descriptor Table" (short: IDT) is also available from all programs. |
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http://microlabs.cs.utt.ro/~mmarcu/books/03/p_all5.htm
(207 words)
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| | Debugging Session |
| | In fact the VMT is prefixed with many special fields including the pointer to the class RTTI, the pointer to the published field table, the pointer to the published method table, and so on. | | | The virtual method table entry constants define positions that precede any given class VMT, which are occupied by pointers to other compiler-generated information, such as the class name and the RTTI table. | | | As a convenience, the System unit defines a number of constants defined to represent each of these fields in terms of their relative offsets from the VMT start, as mentioned earlier. |
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http://www.blong.com/Conferences/DCon2000/Debugging/Debugging.htm
(207 words)
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| | CSc882 Research Paper Java Optimization and Performance |
| | Since all Java methods are considered virtual the overhead associated with a virtual method table (VMT) cannot be optimized. | | | Javac fails to take into account the fact that methods called during evaluation of the conditional may have side effects such as throwing exceptions or assigning to class variables. | | | The Java Virtual Machine places some restrictions on what and where the developer can actually optimize. |
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http://www.cs.gsu.edu/~cscrlb/csc882/node1c.html
(207 words)
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| | Data Pump Export and Import |
| | The create table statements were all commented out in the indexfile, but a bit of text file editing would nevertheless have made the indexfile a workable DDL generation script… providing you weren’t interested in creating anything other than indexes or tables, of course, because things like ‘create procedure’ statements just didn’t get included. | | | A Data Pump import job can change tablespace names found in the source dump file set… so there should be no more mucking around trying to edit a binary file, or fiddling with user permissions and default tablespaces, simply to get a table created in a tablespace with a different name than it came from. | | | This table is known generically as the ‘Master Table’ or MT for short (and in the Oracle documentation). |
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http://www.dizwell.com/html/data_pump.html
(207 words)
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| | OraFAQ Forum: Warehouse Builder => Create FACT and DIMENSION table commands |
| | Other than the CREATE TABLE command in ORACLE, are there any other CREATE commands specifically for FACT or DIMENSION tables? | | | Re: Create FACT and DIMENSION table commands [message #92855 is a reply to message #92853 ] | | | With the dimension table creation wizard you can create the respective attributes and hierarchy. |
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http://www.orafaq.com/forum?t=msg&th=35316/0
(202 words)
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| | Moya K. Mason -- Resume -- MLIS, Freelance Researcher, Internet Searcher, Fact Checker, Research Consultant, Writer, Editor, and Information Scientist |
| | I also did original research, summarized our research materials, compiled sources, wrote, fact-checked, and formatted Word for the manuscript to create table of contents and endnotes (including formatting them into the Chicago Style). | | | My specific duties included collection of the survey data, inputting it all into Excel, creating a series of tables and charts, and helping to analyze the findings. | | | I also created two separate Word files to hold almost 900 long answers for the qualitative data that helped draw a portrait of what the respondents thought. |
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http://moyak.com/researcher/resume/index.html
(5937 words)
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