FILE ORGANIZATIONS:
*File Organization refers to the logical relationships among various records that constitute the file.
*Storing the files in certain order is called file Organization.
* File Structure refers to the format of the label and data blocks and of any logical control record.
*File mean collection of related information that is recorded on secondary storage such as magnetic disks, magnetic tables and optical disks.
TYPES OF FILE ORGANIZATIONS:
- Sequential File Organization
- Heap File Organization
- Hash File Organization
- B+ Tree File Organization
- Clustered File Organization
1.Sequential File Organization:
*Records are stored one after the other as they are inserted into the tables.
*This method is called pile file method. When a new Record is inserted, it is placed at the end of the file.
*In the case of any modification or deletion of record, the record will be searched in the memory blocks.
2.Heap File Organization:
*When the data block is full, the new record is stored in some other block.
*This new data block need not to be the very next data block, but it can select any data block in the memory to store new records.
*The heap file is also known as an unordered file.
3.Hash File Organization:
*Hash File Organization uses the computation of hash function on some fields of the records.
*The hash function's output determines the location of disk block where the records are to be placed.
* when a new record has to be inserted, then the address is generated using the hash key and record is directly inserted.
4.B+ Tree File Organization:
*B+ Tree is an advanced method of ISAM file organization.
*It uses the same concept of key-index, but in a tree like structure.
*B+ tree is similar to binary search tree, but it can have more than two leaf nodes.
5.Clustered File Organization:
*File contains single table and are all stored in different ways in the memory.
*If two or more table which are frequently used to join and get the results are stored in the same file called clusters.
*This method reduces the cost of searching for various records in different files.
