Re: pg_system_identifier()

<p dir="ltr"><br /> Dne 17. 9. 2013 17:01 "Andres Freund" <<a
href="mailto:andres@2ndquadrant.com">andres@2ndquadrant.com</a>>napsal(a):<br /> ><br /> > On 2013-09-17
10:57:46-0400, Robert Haas wrote:<br /> > > On Mon, Sep 16, 2013 at 1:25 AM, Satoshi Nagayasu <<a
href="mailto:snaga@uptime.jp">snaga@uptime.jp</a>>wrote:<br /> > > > How about adding new system view with
newfunction which returns<br /> > > > a single pg_controldata value in text type, and using a cast for<br />
>> > each column in the view definition?<br /> > > ><br /> > > > CREATE VIEW
pg_catalog.pg_controldataAS<br /> > > >   SELECT pg_controldata('control_version')::integer AS
control_version,<br/> > > >          pg_controldata('catalog_version')::integer AS catalog_version,<br /> >
>>          pg_controldata('system_identifier')::bigint AS system_identifier,<br /> > > >        
 ...<br/> > > >          pg_controldata('next_xlog_file')::char(25) AS next_xlog_file,<br /> > > >  
      ...<br /> > > >          pg_controldata('encoding')::text AS encoding;<br /> > > ><br /> >
>> Given that the view can work like a SRF, and it allows us to retrieve<br /> > > > all the values of
pg_controldatawith appropriate types in single<br /> > > > record from the view:<br /> > ><br /> >
>I like this idea.  I think having an easy way to get the values with<br /> > > the right types will be a
plus. But adding a separate function for<br /> > > each field seems excessive, so I think this is a good
compromise.<br/> ><br /> > Why not add a single function returning a composite type then? That'd at<br /> >
leasthave a chance of returning consistent values for the individual<br /> > values that change during runtime. It
wouldalso produce proper errors<br /> > when you load a view using columns that don't exist anymore instead of<br />
>just at runtime.<br /> ><br /><p dir="ltr">+1<p dir="ltr">Pavel<p dir="ltr">> Greetings,<br /> ><br />
>Andres Freund<br /> ><br /> > --<br /> >  Andres Freund                     <a
href="http://www.2ndQuadrant.com/">http://www.2ndQuadrant.com/</a><br/> >  PostgreSQL Development, 24x7 Support,
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