Oracle includes numerous data structures to improve the speed of Oracle SQL queries. Oracle includes many new indexing algorithms that dramatically increase the speed with which Oracle queries are serviced like b-tree index, bitmap indexes, function-based indexes, and index-only tables (IOTs
Oracle uses indexes to avoid the need for large-table, full-table scans and disk sorts, which are required when the SQL optimizer cannot find an efficient way to service the SQL query. I begin our look at Oracle indexing with a review of standard Oracle b-tree index methodologies.
To drop an index in a database, you need to use a specific SQL command. First, you identify the name of the index you want to drop. Then, you use the DROP INDEX statement followed by the name of the index. This command removes the index from the database, making the associated data searchable without the index.
Index on a table in the database is just like an index (or content page) in a book - a quick look at an index can tell you where the actual data is located. This saves time and cost of scanning the whole table, thus making the database faster.
It is a database, either a manual card index or an electronic computer system.
The word database is a noun that means a collection of data. Some words that are synonyms for database are directory, index, and table.
A database, as used by a computer, is a software programme that is used to store data (information). A card index is also a database, written on pieces of card - so, technically, a card index is a physical thing (hardware?), possibly.
Table, index, trigger and column Table, index, trigger and column
Vague question, but if you are talking about a database field, the simple way is to create a unique index on the field (if the database supports it). The index will not allow duplicate values to be added to the database for that field and will generate an error if somebody tries.
index field
Database indexes do not contain data; they are structures that improve the speed of data retrieval.
CDX are theCompound Index File. CDX are Index of files or other data contained in a database; similar to a compact index (.IDX) file, but the leaf nodes at the lowest level of a compound index point to one of the tags in the index. . Such kind of files can be opened by Microsoft Visual FoxPro or Any other database compatible software.
A key is a unique part of the record that is used to index.
The index between relations databases is the common thread which ties them together. So if you have a column in each database called 'idnum' and IDNUM:001 in the first database corresponds with data in IDNUM:001 in the second database, the two databases are relational and IDNUM is their index.