Search results
Results from the WOW.Com Content Network
A multivalued dependency is a special case of a join dependency, with only two sets of values involved, i.e. it is a binary join dependency. A multivalued dependency exists when there are at least three attributes (like X,Y and Z) in a relation and for a value of X there is a well defined set of values of Y and a well defined set of values of Z ...
In Lua, "table" is a fundamental type that can be used either as an array (numerical index, fast) or as an associative array. The keys and values can be of any type, except nil. The following focuses on non-numerical indexes. A table literal is written as { value, key = value, [index] = value, ["non id string"] = value }. For example:
In general, the join and meet of a subset of a partially ordered set need not exist. Join and meet are dual to one another with respect to order inversion. A partially ordered set in which all pairs have a join is a join-semilattice. Dually, a partially ordered set in which all pairs have a meet is a meet-semilattice.
input_lines = LOAD '/tmp/my-copy-of-all-pages-on-internet' AS (line: chararray);-- Extract words from each line and put them into a pig bag-- datatype, then flatten the bag to get one word on each row words = FOREACH input_lines GENERATE FLATTEN (TOKENIZE (line)) AS word; -- filter out any words that are just white spaces filtered_words = FILTER words BY word MATCHES '\\w+';-- create a group ...
PerlMonks – a community committed to sharing Perl knowledge and coding tips; Free Perl tutorials. Perl in 10 easy lessons at Linux Forums; Perl Maven Tutorial – a beginner and an advanced tutorial; Learn Perl in about 2 hours 30 minutes – introductory tutorial; Introductory Perl Tutorial Course for Windows – includes CGI instruction.
Originally, filehandles could only be created with package variables, using the ALL_CAPS convention to distinguish it from other variables. Perl 5.6 and newer also accept a scalar variable, which will be set (autovivified) to a reference to an anonymous filehandle, in place of a named filehandle.
Perl. Block comments in Perl are considered part of the documentation, and are given the name Plain Old Documentation (POD). Technically, Perl does not have a convention for including block comments in source code, but POD is routinely used as a workaround. PHP. PHP supports standard C/C++ style comments, but supports Perl style as well. Python
In computer science, a dispatch table is a table of pointers or memory addresses to functions or methods. [1] Use of such a table is a common technique when implementing late binding in object-oriented programming .