<div dir="ltr">Hi,<br /><br />Please find the results for the following 3 scenarios with unpatched master:<br /><br
/>1.Default settings for *_flush_after : TPS = <b>10677.662356</b><br />2. backend_flush_after=0, rest defaults : TPS =
<b>18452.655936</b><br/>3. backend_flush_after=0, bgwriter_flush_after=0,<br />wal_writer_flush_after=0,
checkpoint_flush_after=0: TPS = <b>18614.479962</b><br /><br />With Regards,<br />Ashutosh Sharma<br />EnterpriseDB: <a
href="http://www.enterprisedb.com">http://www.enterprisedb.com</a><br/></div><div class="gmail_extra"><br /><div
class="gmail_quote">OnFri, May 13, 2016 at 7:50 PM, Robert Haas <span dir="ltr"><<a
href="mailto:robertmhaas@gmail.com"target="_blank">robertmhaas@gmail.com</a>></span> wrote:<br /><blockquote
class="gmail_quote"style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On Fri, May 13,
2016at 7:08 AM, Ashutosh Sharma <<a href="mailto:ashu.coek88@gmail.com">ashu.coek88@gmail.com</a>> wrote:<br />
>Following are the performance results for read write test observed with<br /> > different numbers of
"backend_flush_after".<br/> ><br /> > 1) backend_flush_after = 256kb (32*8kb), tps = 10841.178815<br /> > 2)
backend_flush_after= 512kb (64*8kb), tps = 11098.702707<br /> > 3) backend_flush_after = 1MB (128*8kb), tps =
11434.964545<br/> > 4) backend_flush_after = 2MB (256*8kb), tps = 13477.089417<br /><br /></span>So even at 2MB we
don'tcome close to recovering all of the lost<br /> performance. Can you please test these three scenarios?<br /><br
/>1. Default settings for *_flush_after<br /> 2. backend_flush_after=0, rest defaults<br /> 3. backend_flush_after=0,
bgwriter_flush_after=0,<br/> wal_writer_flush_after=0, checkpoint_flush_after=0<br /><div class="HOEnZb"><div
class="h5"><br/> --<br /> Robert Haas<br /> EnterpriseDB: <a href="http://www.enterprisedb.com" rel="noreferrer"
target="_blank">http://www.enterprisedb.com</a><br/> The Enterprise PostgreSQL Company<br
/></div></div></blockquote></div><br/></div>