Data distribution in other RDBMS
It is sequential so, storing and retrieve take time So that take lot of time storing and retrieval
Data distribution in tera data
- a) Automatic A sit is automatic, it loads any volume of data
- b) uniform(or) even(or)randomly It loads the data uniformly or parallel so that distribution and retrieval faster.
This automatic and uniform event is possibly in tera data, because of indexes.
Data Access Mechanism
- a) Full table scan (FTS)
- b) Primary index retrieval (P.I)
- c) Secondary index retrieval(S.I)
A) FULL TABLE SCAN(FTS)
i) System performance
In case of FTS System performance decreased
ii) Situation to Get
a) If the indexed columns are not used in the query
b) An index is used in non-equal to test
c) Range of value specified in primary index
Ex:-
b)Sel*from party where party name like’V%’
- C) Sel* from party where party income between 5000 and 7000
FTS Process
- i) It scans every data block in table
- ii) All Amp scan for the table portion
Remedy
Take appropriate PI to avoid FTS
To Apply PI to avoid FTS
To used PI to avoid FTS.