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how can i calculate a COLUMN size in a COLUMN TABLE?

Nov 11, 2016 at 12:33 PM

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dear all, i thought i knew what i was doing, but i must be missing something, that i hope someone can point out.

I have a table “MYTABLE” with a single column “COL1”, data type CHAR(17).

There are 10,000,000 records in the MYTABLE.

There are 111 distinct records

Based upon my calculations

The Dictionary table should 1,887 bytes (111 * 17)

The Vector table “value id” can be 7 bits to handle 111 unique values, so should be 70,000,000 bits for all 10M records (10,000,000 * 7 ) = 8,750,000 Bytes

Add them together, you get 8,751,887 Bytes or 8,752 KB

So, why do i see 62 KB

looking forward to hearing from you

g

col.png (26.0 kB)
10 |10000 characters needed characters left characters exceeded

anyone bold enough to have a go at this ?

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