Beefy Boxes and Bandwidth Generously Provided by pair Networks
"be consistent"
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

You might want to look into the documentation for your database, as there's likely a bulk-loading ability to handle this sort of replacement.

In Oracle, it's the command 'sqlldr'. For mysql, use the 'LOAD DATA LOCAL INFILE' command with the 'REPLACE' keyword. (note -- removing the LOCAL keyword will likely result in a failure on permissions).

There are also tricks that you can use when handling this size of table -- I copy the table, drop all indexes, load the data, then recreate the indexes and replace the original table. This saves the indexes needing to update for each insertion. With oracle, you can defer constraints, so they're done in mass. (but, if you screw up, you have to roll back the entire transaction).

For comparison ... I updated a mysql table this morning (6.2 million records), using 'LOAD DATA' in under 7.5 min:

mysql> LOAD DATA LOCAL INFILE '/tmp/HINODE_sizes.txt' REPLACE INTO TAB +LE hinode.files ( filepath, instrument, quicklook, mod_time, filesize + ); Query OK, 11884251 rows affected, 1 warning (7 min 26.99 sec) Records: 6264061 Deleted: 5620190 Skipped: 0 Warnings: 1

In your example, if your primary key is 'vc', you should be able to load it as a pipe delim file


In reply to Re: DBI: How to update 150K records efficiently by jhourcle
in thread DBI: How to update 150K records efficiently by lihao

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others examining the Monastery: (14)
    As of 2014-09-30 19:14 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      How do you remember the number of days in each month?











      Results (381 votes), past polls