X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fmathql%2Fhomepage%2Fwhatsnew.html;h=1a15631ba5f1ba3ca03324c2eab1ba2c307a94cb;hb=caaca5ed51e45a023ccb1244fd5cbbb32d233e2e;hp=e00096b641cb838c1f80638ce34da99f12e6cc9b;hpb=686e22323249fbfdaf21f53b5a11fe73df52f3b9;p=helm.git diff --git a/helm/mathql/homepage/whatsnew.html b/helm/mathql/homepage/whatsnew.html index e00096b64..1a15631ba 100644 --- a/helm/mathql/homepage/whatsnew.html +++ b/helm/mathql/homepage/whatsnew.html @@ -3,267 +3,326 @@
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What's new
- This page reports the newly implemented
- features of MathQL-1 that are not included in the official
+
+ This page reports the newly implemented
+ features of MathQL-1 that are not included in the official documentation yet.- - - - -
-
+ Changes and additions to MathQL-1 operators:-+ + + MathQL-1 version 4 now under development ...+We are now implementing the new unstable version of MathQL-1 (i.e. MathQL-1.4). +The main goals of this release are:
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+ Changes and additions to MathQL-1 operators:+
The syntax now is:- + <query> := "add" [ "distr" ]? [ <groups> | <avar> ] "in" <query>- + <groups> := <group> [ ";" <group> ]* + <group> := <attribute> [ "," <attribute> ]* + <attribute> := <value> "as" <path> + + Examples: + the query add "1" as "a", "2" as "b" in subj "A" gives the result + "A" attr {"a"="1"; "b"="2"} while + the query add "1" as "a"; "2" as "b" in subj "A" gives the result + "A" attr {"a"="1"}, {"b"="2"}. + +
<value> := "align" <string> "in" <value>- + + This operators aligns strings containing numbers so that their alphabetic + order agrees with their numeric order. + +
- -
+
+ The PostgreSQL database map is a file describing how the MathQL-1
+ interpreter must interact with the underlying PostgreSQL database, when
+it is run in Postgres mode. Currently this file contains the following information:+ + + The PostgreSQL database map:-+ +
-The first line must contain the database connection string and the subsequent -lines contain the map with the following syntax: + The format of the file is textual and line oriented, but a corresponding + XML syntax will be provided soon. + The first line must contain the database connection string and the subsequent + lines contain the map with the following syntax: +
the information about the metadata denoted by the given -path is found in the given field of the given table in the database. For + path is found in the given field of the given table in the database. For example the line:+ + refobj h_occurrence <- refObj h:occurrence + + tells that the metadata denoted by the path /"refObj"/"h:occurrence" + is found in the field "h_occurrence" of the table "refobj" in the database, + while: + + refobj source <- + + tells that the metadata denoted by the path / is found in the field + "source" of the table "refobj" in the database; + +
same as the previous but defines a default table and field -for the given path. This is used to force the interpreter to query a particular -table when the information denoted by a path can be found in more than one -table and field. For example:+ for the given path. This is used to force the interpreter to query a particular + table when the information denoted by a path can be found in more than one + table and field. For example: + + objectname source <+ + refobj source <- + refrel source +<- + refsort source <- + + tells that the metadata denoted by the path / is found in the "source" + field of the "objectname", "refobj", "refrel" and "refsort" tables, and +that the first choice is preferred; + +
the given path denotes a structured metadata whose components -are found in the fields of the given table. For example:+ are found in the fields of the given table. For example: + + refobj <- refObj + + tells that the path /"refObj" denotes a structured metadata whose + components are found in the fields of the table "refobj"; + +
same as the previous but tells that this is a default correspondence; -+ + +
defines a correspondence between a virtual table name an -a concrete table name. All the <table_name> entries represent virtual -table names that are mapped to concrete table names using the identity function -unless a particular mapping is defined for them using the above construction. -This mechanism allows to define several set of metadata on the same database -table as in:+ a concrete table name. All the <table_name> entries represent virtual + table names that are mapped to concrete table names using the identity function + unless a particular mapping is defined for them using the above construction. + This mechanism allows to define several set of metadata on the same database + table as in: + + refobj source + <- + refobj h_occurrence <- + refObj h:occurrence + backpointer source + <- backPointer h:occurrence + backpointer h_occurrence <- + backpointer + -> refobj + + which defines four path accessing two virtual tables ("refobj" -and "backpointer") and then maps these tables in a single concrete table;+ and "backpointer") and then maps these tables in a single concrete table; + +
a line like this must end the map file.-Here you can find the + Here you can find the current -version of PostgreSQL database map for HELM. - - How does the interpreter use the map? The map file is read during -the interpreter initialization process from the file pointed by the MATHQL_DB_MAP -environment variable and is used during the execution of each property -operation in the issued queries.When executing a property operation, -the interpreter uses the map to find the smallest set of database tables -containing the information required by the given access paths and then queries -these tables to obtain the wanted information. - |
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