How do I narrow my search results?
After you submit your search query:
- On the Refine Search results page, select one or more categories of products or services from the left sidebar.
- Then for a category with search results, click Select to choose your product and release filters, and then click OK.
For search queries that contain multiple words, surround the query with quotes, and then resubmit your query. Example: "database cloud service"
How do I find the documentation for my product or service?
From the home page, click the technology categories for your products or services. If you do not know which category to pick, try the following features:
- Click the Find a product tab and search for your product or service.
- Click Browse All Products & Services at the bottom of the home page to view an alphabetical listing of products and services.
- Apple Safari: Version 6
- Google Chrome: Version 29 and later
- Mozilla Firefox: Version 24 and later
- Microsoft Internet Explorer: Version 9 and later
DROP INDEX → Purpose Use the DROP INDEX statement to remove an index or domain index from the database. When you … drop an index, Oracle Database invalidates all objects that depend on the underlying table … index, a range-partitioned index, or a hash-partitioned index, all the index
ALTER INDEX → Purpose Use the ALTER INDEX statement to change or rebuild an existing index. See Also: CREATE … INDEX for information on creating an index Prerequisites The index must be in your own schema or you … must have ALTER ANY INDEX system privilege. To execute the MONITORING USAGE clause,
CREATE INDEX → Purpose Use the CREATE INDEX statement to create an index on: One or more columns of a table, a … partitioned table, an index-organized table, or a cluster One or more scalar typed object attributes of … a table or a cluster A nested table storage table for indexing a nested table column An index is a … index:
Rebuild Index Coalesce Index → Quickly moves index to another tablespace Cannot move index to another tablespace Higher costs … storage and tablespace parameters without having to drop the original index. Quickly frees up index leaf … blocks for use. In situations where you have B-tree index leaf blocks that can be freed up for reuse
Choosing and Monitoring a Threshold Value → Choose a threshold value that can accommodate your key columns, as well as the first few nonkey columns (if they are frequently accessed). After choosing a threshold value, you can monitor tables to verify that the value you specified is appropriate. You can use the ANALYZE TABLE... LIST CHAINED ROWS statement to determine the number and identity of rows exceeding the threshold value. See Also: \"Listing
Creating a Secondary Index on an Index-Organized Table → The following statement shows the creation of a secondary index on the docindex index-organized … table where doc_id and token are the key columns: CREATE INDEX Doc_id_index on Docindex(Doc_id, Token … ); This secondary index allows the database to efficiently process a query, such as the following, the
Collecting Optimizer Statistics for Index-Organized Tables → gathers statistics for the index-organized countries table in the hr schema: EXECUTE … DBMS_STATS.GATHER_TABLE_STATS ('HR','COUNTRIES'); The DBMS_STATS package analyzes both the primary key index segment … physical statistics of the primary key index segment using USER_INDEXES, ALL_INDEXES or DBA_INDEXES … (and using the primary
Restrictions for Index-Organized Tables → The following are restrictions on creating index-organized tables. The maximum number of columns is … 1000. The maximum number of columns in the index portion of a row is 255, including both key and … size of a row exceeds 50% of the index block size and you do not specify an overflow segment, the … CREATE TABLE statement fails.
Analyzing Index-Organized Tables → Just like ordinary tables, index-organized tables are analyzed using the DBMS_STATS package, or the ANALYZE statement.
Maintaining Physical Guesses in Logical Rowids → through the primary key-component of the logical rowid, but access to rows is slower. Collect index … (and related views). To obtain fresh guesses, you can rebuild the secondary index. Note that … rebuilding a secondary index on an index-organized table involves reading the base table, unlike rebuilding … an index
Converting Index-Organized Tables to Regular Tables → You can convert index-organized tables to regular tables using the Oracle import or export … utilities, or the CREATE TABLE...AS SELECT statement. To convert an index-organized table to a regular table … : Export the index-organized table data using conventional path. Create a regular table definition … with the same definition.
Example: Creating an Index-Organized Table → The following statement creates an index-organized table: CREATE TABLE admin_docindex( token char … pk_admin_docindex PRIMARY KEY (token, doc_id)) ORGANIZATION INDEX TABLESPACE admin_tbs PCTTHRESHOLD 20 OVERFLOW … TABLESPACE admin_tbs2; This example creates an index-organized table named admin_docindex, with a … if the length
Creating Index-Organized Tables that Contain Object Types → Index-organized tables can store object types. The following example creates object type admin_typ … , then creates an index-organized table containing a column of object type admin_typ: CREATE OR … primary key, c2 admin_typ) ORGANIZATION INDEX; You can also create an index-organized table of object … types. For
Using Key Compression → Creating an index-organized table using key compression enables you to eliminate repeated … occurrences of key column prefix values. Key compression breaks an index key into a prefix and a suffix entry … . Compression is achieved by sharing the prefix entries among all the suffix entries in an index … block. This sharing can lead
Altering Index-Organized Tables → All of the alter options available for ordinary tables are available for index-organized tables … an index-organized table cannot be dropped, deferred, or disabled You can use the ALTER TABLE … statement to modify physical and storage attributes for both primary key index and overflow data segments … . All the attributes specified
Moving (Rebuilding) Index-Organized Tables → Because index-organized tables are primarily stored in a B-tree index, you can encounter … to rebuild the index and reduce this fragmentation. The following statement rebuilds the index … -organized table admin_docindex: ALTER TABLE admin_docindex MOVE; You can rebuild index-organized tables
Using the ORDER BY Clause with Index-Organized Tables → If an ORDER BY clause only references the primary key column or a prefix of it, then the optimizer avoids the sorting overhead, as the rows are returned sorted on the primary key columns. The following queries avoid sorting overhead because the data is already sorted on the primary key: SELECT * FROM admin_docindex2 ORDER BY token, doc_id; SELECT * FROM admin_docindex2 ORDER BY token; If, however,
Managing Index-Organized Tables → This section describes aspects of managing index-organized tables, and contains the following … topics: What Are Index-Organized Tables? Creating Index-Organized Tables Maintaining Index-Organized … Tables Creating Secondary Indexes on Index-Organized Tables Analyzing Index-Organized
Using the INCLUDING Clause → including the column specified in the INCLUDING clause in the index leaf block, provided it does not … an example:CREATE TABLE admin_iot4(a INT, b INT, c INT, d INT, primary key(c,b)) ORGANIZATION INDEX … CREATE TABLE statement is similar to the one shown earlier in \"Example: Creating an Index-Organized … Table\" but is modified
Maintaining Index-Organized Tables → Index-organized tables differ from ordinary tables only in physical organization. Logically, they … are manipulated in the same manner as ordinary tables. You can specify an index-organized table just