diff between OLTP and OLAP?
what TOP-DOWN and BOTTOM-UP Approach? which is best?
what are Star Schema and Snow Flake Schema?
Answer Posted / vijay sampoorna
oltp:
1) oltp has current and upated data
2)it is denarmalized
3)it has detailed data
4)it volatail
5) it is dynamic
OLAP:
1)it has current and histarical data
2) it is normalized
3) it has summarised data
4) it is non volatail
5) it is static
top down aproch;
first construct the enteir d.w.h then devided into data marts
Bottom down Aproch:
1)first build datamarts
2) then we build data where houses
star schema:
one fact table sorunded by one or more demintaion tables is calld star schema
it is use less memory
it performence is fast
it contain data duplicates
Snow-flake Schema:
one fact table soround by one or more demintion table that tables can splited into n dimentinos
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