select*from vit;

selectcount(*)from vitwhere t='min'::text;

selectcount(*)from vitwhere i>='1 minute'::interval;

createtablestock(symbolchar(5), daydate, lowreal, highreal, openreal, closereal);

insert into stockvalues

('AAA','01-11-2018',10.0,11.0,10.1,10.8),

('AAA','02-11-2018',11.0,12.0,11.2,11.5),

('AAA','03-11-2018',10.4,10.6,10.5,10.4),

('AAA','04-11-2018',11.1,11.5,11.2,11.4),

('AAA','05-11-2018',11.0,11.3,11.4,11.1);

select create_projection('vstock','stock',array['day','low','high','open','close'],array['symbol'],'day');

select vstock_refresh();

selectavg((open+close)/2),max(high-low)from stockgroup by day;

setvops.auto_substitute_projections=on;

explain (costs off)selectavg((open+close)/2),max(high-low)from stockgroup by day;

selectavg((open+close)/2),max(high-low)from stockgroup by day;

insert into stockvalues

('AAA','06-11-2018',10.1,10.8,10.3,10.2),

('AAA','07-11-2018',11.1,11.8,10.2,11.4),

('AAA','08-11-2018',11.2,11.6,11.4,11.3),

('AAA','09-11-2018',10.6,11.1,11.3,10.8),

('AAA','10-11-2018',10.7,11.3,10.8,11.1);

select vstock_refresh();

selectavg((open+close)/2),max(high-low)from stockgroup by day;

setvops.auto_substitute_projections=off;

selectavg((open+close)/2),max(high-low)from stockgroup by day;

sep :=',';

if att_name=order_by

then

key_type= typname;

key_type:= att_typname;

end if;

end loop;

execute create_index;

if key_type='timestamp'or key_type='date'

then

min_value :='''-infinity''';

min_value :='''''-infinity''''::'||key_type;

else

min_value :='-1';-- assume that key have only non-negative values

end if;

Oidtype_id=DatumGetObjectId(SPI_getbinval(spi_tuple,spi_tupdesc,2,&is_null));

types[i].tid=vops_get_type(type_id);

get_typlenbyvalalign(type_id,&types[i].len,&types[i].byval,&types[i].align);

if (types[i].len<0) {/* varying length type: extract size from atttypmod */

if (types[i].tid!=VOPS_LAST&&types[i].len<0) {/* varying length type: extract size from atttypmod */

types[i].len=DatumGetInt32(SPI_getbinval(spi_tuple,spi_tupdesc,3,&is_null))-VARHDRSZ;

if (types[i].len<0) {

elog(ERROR,"Size of column %s is unknown",name);

<li>Query performs aggregation of vector (tile) columns.</li>

<li>All other expressions in target list,<code>ORDER BY</code> /<code>GROUP BY</code> clauses refers only to scalar attributes of projection.</li>

Projection can be removed using<code>drop_projection(projection_name text)</code> function.

It not only drops the correspondent table, but also remove information about it from<code>vops_partitions</code> table

and drops generated refresh function.

<h2><aname="example">Example</a></h2>