Re: [HACKERS] distibuted transactions, SQL+XPath+XTree
Richard, >> I see the following business opportunity for Postgres: >> I) Simple man can't program middleware to connect XML-client and >> Postgres. RH> Aha! still trying to push an XML command system and http server into the RH> backend. Yes. >> II) Request into several databases does not exist. RH> what you do with cross-database dependencies As i understand, you are saying about inter-database FK connect address www.default.bz; create nick db1 address www.site.com; create nick db2 address www.data.net; connect addr=“www.data.net” user=“Smith” pwd=“qxuwb”; create table b ( b1 xml, b2 number, b3 xml ); connect addr=“www.site.com” user=“Tomson” pwd=“ncwhif”; create table a ( a1 number references db1:b(@b1/k/m/@m1), a2 xml, foreign key (@a2/p/q/@q1) references db1:b(@b2), a3 xml, foreign key (@a3/p/q/@q1) references db1:b(@b3/k/m/@m1) ); e.g. slides #75-76 in http://sql50.euro.ru/sql5.11.3.ppt ? There are two case, which i'm naming 'set' ( a<= b, slide #93-94) and 'relay-rece' ( a => b , slide #95-98). I propose to not try all "second" database, i.e. to not use reference from "second" database to "first" database (case of 'set'). Case 'relay-race' works clearly. Of course, i raise question about designation of interbase FK in modellers (slide #105). >> III) Notebooks need several switching-on and switching-off during >> transaction. RH> How are you dealing with the locking issues? I propose to freeze transaction (#118): create user u identified by p waited 1.0/0; -- yy.mm.dd/hh.mm.ss; freeze; -- like disconnect - unfreeze addr=site.com user=Tomson pwd=ncwhif safe=8726; -- like ‘connect’ unfreeze addr=data.net user=Smith pwd=qxuwb safe=9278; P.S. Of course, i propose possibility to freeze failed commit (#120). >> IV) Distance between strings are not supported, that makes >> aproximate searching impossible. RH> Would that be "not supported" in the sense of "contrib/fuzzystrmatch"? I propose 1) to use Levenshtein distance recursively: for letters in words, for words in phrases (separated by marks of punctuation), for phrases (e.g. sentances) in string 2) to count convolutions (several words into abbreviation, and back) >> V) There is no possibility to hide some (not all) records of table, >> granted to other users, from these users RH> Apart from views depending of user, which look in view RH> or the veil pgfoundry project of course. I'm not understanding, clarify, please. >> I ask you to implement these solutions, that Postgres get >> advantage before other DBMS-es. I have prepered several drawing >> http://sql50.euro.ru/sql5.11.3.ppt to explain ideas. >> More details are described below. RH> Were you looking to hire developers, or do you have customers who are RH> looking to hire developers? Neither this, nor that. I'm looking for volunteers. P.S. I'm also seggesting to implement 1) restricted table for stream processing: create table a ( a1 number, a2 number ) size 5; create table aa (…); -- resize a to 10; -- resize a to infinity; -- redirect a to aa; create table a ( a1 number, a2 number ) size 5 direct aa; 2) timer: create timer TimerName start yy.mm.dd/hh.mm.ss end yy.mm.dd/hh.mm.ss schedule (yy.mm.dd/hh.mm.ss, yy.mm.dd/hh.mm.ss, …) per yy.mm.dd/hh.mm.ss as begin … end; create timer t1 schedule (01/0, 03/0, 10/0) per 01.00/0 as … ; -- 1-st, 3-rd, 10-th day of each month create timer t2 schedule (0/0.05, 0/0.10, 0/0.20) per 0/01 as … ; -- 5-, 10-, 20-th minutes of each hour create timer t3 schedule (0) per 1/0 as … ; -- each day Dmitry Turin SQL5 (5.11.3) http://sql50.euro.ru HTML6 (6. 5.4) http://html60.euro.ru Unicode7 (7. 2.1) http://unicode70.euro.ru Computer2 (2. 0.2) http://computer20.euro.ru ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
Re: [HACKERS] distibuted transactions, SQL+XPath+XTree
Тюрин Дмитрий wrote: Hi list, Hi Dmitry, nice to have you back again. I see the following business opportunity for Postgres: I) Simple man can't program middleware to connect XML-client and Postgres. Aha! still trying to push an XML command system and http server into the backend. II) Request into several databases does not exist. Well, there are middleware layers that'll do so, or various case-specific solutions requiring dblink. The key problem is what you do with cross-database dependencies. How were you thinking of dealing with this? III) Notebooks need several switching-on and switching-off during transaction. How are you dealing with the locking issues? IV) Distance between strings are not supported, that makes aproximate searching impossible. Would that be "not supported" in the sense of "contrib/fuzzystrmatch"? V) There is no possibility to hide some (not all) records of table, granted to other users, from these users Apart from views or the veil pgfoundry project of course. I ask you to implement these solutions, that Postgres get advantage before other DBMS-es. I have prepered several drawing http://sql50.euro.ru/sql5.11.3.ppt to explain ideas. More details are described below. Were you looking to hire developers, or do you have customers who are looking to hire developers? -- Richard Huxton Archonet Ltd ---(end of broadcast)--- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
[HACKERS] distibuted transactions, SQL+XPath+XTree
Hi list, I see the following business opportunity for Postgres: I) Simple man can't program middleware to connect XML-client and Postgres. II) Request into several databases does not exist. III) Notebooks need several switching-on and switching-off during transaction. IV) Distance between strings are not supported, that makes aproximate searching impossible. V) There is no possibility to hide some (not all) records of table, granted to other users, from these users Proposed solutions to these opportunities: I) DBMS inserts into tables and selects from tables along correlation Primary Key - Foreign Key. II) Databases get nicknames, groups of databases get name of group. These names are used in requests. III) Operator to freeze transaction. IV) Operator to order records on base of distance between strings. V) Subdivide records of all tables into classes, specify class number in record. I ask you to implement these solutions, that Postgres get advantage before other DBMS-es. I have prepered several drawing http://sql50.euro.ru/sql5.11.3.ppt to explain ideas. More details are described below. === 1) [slides 2-12] Problem: Browser is very widespread client in epoch of internet. Non-programmers can master 'insert', 'select', 'update', 'delete', but are not capable to use sophisticated syntax of proprietary web-server for input of XML. It's necessary to exclude this syntax, and give possibility to install DBMS and immediately use it, like user install and use Teleport, FlashGet, browser and so on. Solution: DBMS itself must communicate via HTTP, accept XML, and place data from it into tables under some agreement. My proposal about agreement: *) xml-element is written into table with identical name (i.e. tag name coincides with table name), xml-attribute is written into field with identical name (i.e. attribute name coincides with field name); *) tables are bound into tree by values of Primary Keys and Foreign Keys; *) value of primary keys of new record is assigned by trigger. If user uses simple scheme, than this is enough! An ambiguity can exist in complex scheme because of several refering fields, than user must append symbol '#' and name of necessary refering field to end of name of sending XML-tag (it looks like new tag name with symbol '#' inside name). Let's name this by term 'determination' [symbol '$' is used for list to have possibility to solve ambiguity for list simultaneously with ambiguity for enclosed XML-element, i.e. to append two refering field to name of sending XML-tag]. P.S. [slides 13-21] Of course, we spead decision to manual 'insert'. 2) [slides 22-31] Problem: Usage of both SQL/XML-functions, and syntax of proprietary web-server give very bulky code to extract tree as XML. This makes more difficulties for contact of DBMS on CML, GML, HumanML, OPML, RCML, SBML, ebXML, MDDL, RIXML, XBRL, xCBL and other (turing all relational fields into XML-elements is suitable for browser, but not suitable for other cases). Solution: To avoid sophisticated programing, 'select' itself must return data to client (if only 'select' is not used inside 'insert ... select ...'). I propose laconic 'select a.b.c' to select data from tables 'a', 'b', 'c'. Let's name this by term 'XTree' - in analogy with 'XPath'. If user uses simple scheme, than this is enough! An ambiguity can exist in complex scheme because of several refering fields, than user must append symbol '#' and name of necessary refering field to end of table name (it looks like new table name with symbol '#' inside name). Let's name this by term 'refinement'. P.S. [slides 32-39] All possible compositions of determinations in XML-tree and all possible compositions of refinement in 'select' are considered, appropriate XML- and SQL-syntaxes are proposed. P.S. [slides 40-49] Examples of usage of refinement are demonstrated. 3) [slides 50-58] Problem: Non-predictable/non-repeated input data (XML-elements) is written into XML-field of relational table. XQuery is offered to process data in these xml-fields. But user is not capable to manipulate records by SQL and XML-elements by XQuery in one request (even in case of refusal from relational storage in favour of XML-database, that means in favour of non-relational 'engine', enclosed cycles of XQuery create very bulky code, in which user is not orientated). Solution: I propose to append XPath into SQL, that SQL can process XML-elements and attributes (i.e. to avoid XQuery). Thus SQL can process records and XML-elements simultaneously. P.S. [slides 59-72] Of course, we generalize XPath and XTree upto XLang, and consider all possible use cases. --- 4) [slides 73-83-116] Problem: SQL would more flexible and convenient for distributed request (gethering data from several databases and scattering them into several databases), than branded programs; including SQL is more convenient for replication, than branded programs. But there is no necessary syntax.
