Re: Vaccum Query

Vik Fearing <vik.fearing@xxxxxxxxxxxxxxx> · Fri, 5 May 2017 22:03:29 +0200



    On 05/04/2017 02:04 PM, PAWAN SHARMA
      wrote:

    
        Hi All,
        

            Any Idea what happens when we run
                standard vacuum (without full) on a table which has
                exclusive lock (or alter statement is being processed on
                that table).
            What happens in this case ? Will
                vacuum wait for the alter to commit ?
          
        
    Yes.

    
             If so, how long ?
          
        
    Either forever or for however long lock_timeout and/or
    statement_timeout are set to (or any user command like Ctrl+C).

    
             If not, then what ?
          
        
    If any of those limits are reached, the vacuum is cancelled.

    
            And what actions can be taken to
                prevent this ?
          
        
    Prevent what?  Even if the vacuum could run while the other
    transaction had the exclusive lock, it wouldn't be able to do any
    work.

    -- 
Vik Fearing                                          +33 6 46 75 15 36
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support