This discussion is archived
1 Reply Latest reply: Dec 21, 2011 8:34 AM by Charles Lamb RSS

Read operation

906230 Newbie
Currently Being Moderated
Hi all,

Will read operations go to any node if the user doesn’t mind incomplete consistency guarantees (i.e. reads might not see the most recent data)?
Will read operations be served from the master node if the user requires the most recent value for a data item?

Can we choose if we want read operations to the done from the master or not? How can we do that?

By default (if there is no failure) will the read request give the last updated data? Or is it possible to have old values because data are given from a node that has not yet the last value.

Thanks for your response.
  • 1. Re: Read operation
    Charles Lamb Pro
    Currently Being Moderated
    user962305 wrote:
    Will read operations go to any node if the user doesn’t mind incomplete consistency guarantees (i.e. reads might not see the most recent data)?
    See oracle.kv.Consistency. Each type of read operation accepts a Consistency parameter. The request is sent to any node that can satisfy the level of consistency specified.
    Will read operations be served from the master node if the user requires the most recent value for a data item?
    Consistency.ABSOLUTE.

    >
    Can we choose if we want read operations to the done from the master or not? How can we do that?
    Consistency.NONE causes the request to be routed to any node in the rep group. TIME_VALUE routes it to any node that is within the specified delta of the master. Consistency.VERSION routes it to any node that has at least that version.

    >
    By default (if there is no failure) will the read request give the last updated data? Or is it possible to have old values because data are given from a node that has not yet the last value.
    If you do not specify a store-wide default, and you do not specify a Consistency in the read-operation's arguments, it will default to Consistency.NONE.

    Charles Lamb

Legend

  • Correct Answers - 10 points
  • Helpful Answers - 5 points