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Search criteria "temp table" returned 185 result(s). Documentation
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Most data base management systems, including Sybase, Informix, and MS SQL Server, have built-in constructs for the creation and management of temporary relation tables. Oracle 8i does not directly support these structures. This shortcoming can seriously complicate migration from the above systems to Oracle.
This paper is intended primarily to present, discuss, and evaluate ways of duplicating Sybase temporary tables in Oracle 8i. Four primary methods will be examined.
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For certain types of SQL operations, the creation of intermediate result tables can result in stunning performance improvements. We will discuss how you can use the global temporary tables (GTT) syntax to improve the speed of queries that perform complex summarization activities, and how to speed up two-stage queries that perform both summarization and comparison activities.
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Mutating table exceptions occur when we try to reference the triggering table in a query from within row-level trigger code. In this article I'll present and example of how a mutating table exception might occur and a simple method to get round it.
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Let me start by saying that it is much, much easier to set up constraints on a table initially than to try to fix data anomalies after the table is populated. If you only want one instance of a user in the table, then a PRIMARY KEY constraint would definitely be in order. Furthermore, any host application or other procedural code should be able to handle the exception raised when someone or some process tries to insert a duplicate.
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The price of a full table scan is directly related to the number of I/O operations that Oracle has to perform in order to read all data blocks, and inversely related to the number of blocks read in a single I/O operation. Therefore, the more I/O operations required, the higher the full table scan price, and the more blocks read per I/O operation, the lower the price of the access path.
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Updatable Snapshots, a feature of Oracle Enterprise Edition only, is the snapshot, or copy, of a table, or part of a table. This copy can also be updated. Thus, updatable snapshot sites can also propagate any changes made upon them back to the parent.
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Transportable Tablespaces are the most efficient way to move large amounts of data from one Oracle database to another. When combined with a properly designed table partitioning scheme this feature provides an ideal method of refreshing a data warehouse or archiving transactional data quickly and with minimum interruption.
To review, the basic premise of Transportable Tablespace is copying the actual Oracle datafile(s) from one database to another, then exporting metadata from the source database and importing it into the target, thus "plugging in" a tablespace. The export includes descriptions of the tables and other objects contained in the tablespace set, but no actual data, making it much faster than a conventional export. The source database requires the Enterprise Edition license.
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Oracle offers a variety of data structures to help create robust database systems. Oracle supports the full use of binary large objects (BLOB), nested tables, non–first-normal-form table structures (VARRAY tables), and object-oriented table structures. It even treats flat data files as if they were tables within the Oracle database.
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Temporary tablespaces are used to manage space for database sort operations and for storing global temporary tables. For example, if you join two large tables, and Oracle cannot do the sort in memory (see SORT_AREA_SIZE initialisation parameter), space will be allocated in a temporary tablespace for doing the sort operation. Other SQL operations that might require disk sorting are: CREATE INDEX, ANALYZE, Select DISTINCT, ORDER BY, GROUP BY, UNION, INTERSECT, MINUS, Sort-Merge joins, etc.
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Standard ASCII code table - shows decimal, hexidecimal, octal and char translations. Very useful.
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