temporary blocking google crawler, will it prevent future indexing?

Sometimes I need to add several updates to my site. To keep it clean I开发者_运维百科 display a maintenance page. The first time I did this it became the main indexed page on google. Therefore I added the meta tag <META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW"> to prevent this. My question is if google comes across this temporary maintenance page he will not index it but does that mean he will never index that page again? or will they index the page again once there is new content?

I would really appreciate if someone could clear this up for me

Google has a guideline for dealing with planned maintenance/downtime: "How to deal with planned site downtime". in short you should return a 503 HTTP result code on those page(s) which are under maintenance or are down. here is an example php code to use on top of those page(s):

header('HTTP/1.1 503 Service Temporarily Unavailable');

if you know exact/approximate time/date of when maintenance/downtime will be complete you can use an optional Retry-After header like this (alongside with above 503 HTTP result code):

//when the exact completion time is known.
header('Retry-After: Sat, 8 Oct 2011 18:27:00 GMT');

or

//when the length of the downtime in seconds is known.
header('Retry-After: 86400');

for more information read google article .

Google's crawler will reindex your site once you remove that meta tag (it is constantly updating its indices).

If you're really paranoid, I'd suggest checking out Google's Webmaster Tools so that you can directly control the indexing behavior of your site: http://www.google.com/webmasters/