Funzione analitica oracle per ottenere il valore del record precedente

lag (expression) over (order-by-clause)
lag (expression, offset) over (order-by-clause)
lag (expression, offset, default-value) over (order-by-clause)

lag (expression) over (query-partition-clause, order-by-clause)

lag is an Analytical function that can be used to get the value of an attribute of the previous row. If you want to retrieve the value of the next row, use lead instead of lag.

The following example will demonstrate this:

A table is created with two attributes: N and M.

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create table lag_exp (
  n number,
  m number
);

insert into lag_exp 
  select rownum, mod(rownum * 19 , 13) 
    from all_objects 
   where rownum < 21;

The following select statement will return n and m and additionally a column with the value of M in the previous row:

select n, m, lag(m,1) over (order by n) "Previous M" from lag_exp;

Settare una acl su cartella linux

• Assign ACL group permission read/write (rw) to a single group: setfacl -m g:groupname:rw- filename
  Option -m : Modify the ACL
• Assign ACL group permission read/write (rw) to a single user: setfacl -m u:userid:rw- filename
• List ACL permissions: getfacl filename
• Remove ACL from a file: setfacl --remove-all filename