# HG changeset patch
# User František Kučera
n.b. the order in 'b|a|c'
does not matter and if such regex matches, it preserves the original order of the attributes;
- but if we specify multiple regexes to specify attributes, their order and count matters:
+ but if we use multiple regexes to specify attributes, their order and count matters:
relpipe-tr-grep run may modify multiple relations or do match on multiple attributes.
+ A tool that drops or multiplies attributes or changes their order (does projection) according to their name match to given regular expression.
+ Relation name is also specified as a regular expression and there might be multiple regexes specifying desired attributes.
+ Thus single relpipe-tr-cut
run may modify multiple relations or pick multiple attributes from them.
+