Re: Inserts and row chaining

ZEITGEIST wrote:

> A co-worker insists that Oracle just keeps inserting bytes until PCTFREE
> is reached, at which point it continues writing the row into another data
> block. I thought Oracle might check to see if the row could be INSERTed
> and, if not, take that block off the free list. Does it then attempt
> to find a less-populated block that can hold the entire row ? I realize
> with LONGs and LONG RAWs, it would never find such a case.
 

> However, I would think that just inserting bytes until PCTFREE was
> reached (and then continuing in another block) would result in a ton of
> chained rows. What am I missing ? I performed a small test and
> my INSERT statements did not create any chained rows.

  The rows can be inserted into the data blocks provided that they are in the freelist. The block can put in the freelist provided that the space usage fell below PCTUSED. As a result, the rows cannot be inserted even though the space usage does not reach PCTFREE.

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Name   : Lun Wing San
Title  : Oracle Application Developer of Hong Kong Productivity Council
         Oracle Database Administrator and System Administrator of QRC
Phone  : (852)27885841