Re: controlling psql's use of the pager a bit more

On 12/21/2014 02:22 PM, Andrew Dunstan wrote:
>
> On 11/15/2014 05:56 PM, Andrew Dunstan wrote:
>>
>> On 11/13/2014 11:41 AM, Andrew Dunstan wrote:
>>>
>>> On 11/13/2014 11:09 AM, Tom Lane wrote:
>>>> Andrew Dunstan <andrew@dunslane.net> writes:
>>>>> I often get annoyed because psql is a bit too aggressive when it 
>>>>> decides
>>>>> whether to put output through the pager, and the only way to avoid 
>>>>> this
>>>>> is to turn the pager off (in which case your next query might dump 
>>>>> many
>>>>> thousands of lines to the screen). I'd like a way to be able to 
>>>>> specify
>>>>> a minumum number of lines of output before psql would invoke the 
>>>>> pager,
>>>>> rather than just always using the terminal window size.
>>>> Are you saying you'd want to set the threshold to *more* than the 
>>>> window
>>>> height?  Why?
>>>
>>>
>>> Because I might be quite happy with 100 or 200 lines I can just 
>>> scroll in my terminal's scroll buffer, but want to use the pager for 
>>> more than that. This is useful especially if I want to scroll back 
>>> and see the results from a query or two ago.
>>>
>>>
>>>
>>>
>>
>>
>> This patch shows more or less what I had in mind.
>>
>> However, there is more work to do. As Tom noted upthread, psql's 
>> calculation of the number of lines is pretty bad. For example, if I do:
>>
>>    \pset pager_min_lines 100
>>    select * from generate_series(1,50);
>>
>> the pager still gets invoked, which is unfortunate to say the least.
>>
>> So I'm going to take a peek at that.
>>
>
>
> The over-eager invocation of the pager due to double counting of lines 
> got fixed recently, so here's a slightly updated patch for a 
> pager_min_lines setting, including docco.
>
>


The assigned reviewer hasn't done a review and hasn't responded to 
email. If there are no other comments I propose to commit this shortly.

cheers

andrew