SQL Tunning - result of set autot traceonly

  I have the Result from traceonly, as below.   My doubt is:

   1.) oracle ran the query from 4 to 25 or it ran from 25 to 4

   2.) What does it mean : 'access'

        Means that the oracle process went to the disk to retrieve data ?

   3.) What does it mean : 'filter'

        Means that oracle process performed a filter in the data that was in memory (cached) ?

   4.) Considering that the item 21 is more selective for query, where must I put it in the statment:

        at the begin of the WHERE CLAUSE or
        at the eng of the WHERE CLAUSE ?

Predicate Information (identified by operation id):

   4 - access("T1"."NUM_DOCUMENTO"="SPL"."NUM_DOCUMENTO" AND "SPL"."NUM_ACIONAMENTO"="VW_COL_1")    5 - access("NUM_DOCUMENTO"="T1"."NUM_DOCUMENTO")

   9 - filter("T1"."UF"='XX')

  10 - access(ROWID=ROWID)

  11 - access(ROWID=ROWID)

  12 - access(ROWID=ROWID)

  13 - access(ROWID=ROWID)

  14 - access(ROWID=ROWID)

  15 - access("T1"."UF"='RS')

  21 - filter("SPL"."STATUS"=2 AND "SPL"."DATA">=TO_DATE(' 2003-12-19 00:00:00', 'syyyy-mm-dd

              hh24:mi:ss') AND "SPL"."DATA"<=TO_DATE(' 2011-07-06 00:00:00', 'syyyy-mm-dd hh24:mi:ss'))

  23 - access("T1"."NUM_DOCUMENTO"="SC"."NUM_DOCUMENTO"(+))

  24 - filter("TC"."N1"='BRT')

  25 - access("T1"."NUM_DOCUMENTO"="TC"."NUM_DOCUMENTO")

Regards
Eriovaldo

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