what are the different types of vsam files available? Explain them
1. Entry sequential data set(ESDS) works like sequential file which contains only cluster and data components.
We must mention NONINDEXED while defining ESDS cluster.
It supports only sequential access in batch program.
2. Key sequential data set(KSDS) has three components(CLUSTER, DATA and INDEX).
We must code INDEXED while defining the KSDS cluster.
Data component consists of sorted records which are based on key values.
Index component consists of key values and the pointer to the data records.
3. Relative Record Data Set(RRDS) records are identified using Relative Record Number (RRN). Records are stored in numbered.
4. The linear dataset(LDS) is a byte-stream dataset which is commonly used in DB2 system. This dataset is rarely used in application programs.
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