Replace the now-incompatible-with-core contrib/tsearch2 module with a

compatibility package.  This supports importing dumps from past versions
using tsearch2, and provides the old names and API for most functions
that were changed.  (rewrite(ARRAY[...]) is a glaring omission, though.)

Pavel Stehule and Tom Lane

1 files changed, 0 insertions, 210 deletions

diff --git a/contrib/tsearch2/README.tsearch2 b/contrib/tsearch2/README.tsearch2
deleted file mode 100644
index 5d7b19d55f..0000000000
--- a/contrib/tsearch2/README.tsearch2
+++ /dev/null
@@ -1,210 +0,0 @@
-Tsearch2 - full text search extension for PostgreSQL
-
-   [1]Online version of this document is available
-
-   Tsearch2  -  is the full text engine, fully integrated into PostgreSQL
-   RDBMS.
-
-Main features
-
-     * Full online update
-     * Supports multiple table driven configurations
-     * flexible  and  rich linguistic support (dictionaries, stop words),
-       thesaurus
-     * full multibyte (UTF-8) support
-     * Sophisticated  ranking  functions  with  support  of proximity and
-       structure information (rank, rank_cd)
-     * Index support (GiST and Gin) with concurrency and recovery support
-     * Rich query language with query rewriting support
-     * Headline support (text fragments with highlighted search terms)
-     * Ability to plug-in custom dictionaries and parsers
-     * Template  generator  for  tsearch2  dictionaries  with [2]snowball
-       stemmer support
-     * It is mature (5 years of development)
-
-   Tsearch2,  in a nutshell, provides FTS operator (contains) for the new
-   data  types,  representing  document  (tsvector)  and query (tsquery).
-   Table  driven  configuration  allows creation of custom searches using
-   standard SQL commands.
-
-   tsvector is a searchable data type, representing document. It is a set
-   of  unique  words  along  with  their  positional  information  in the
-   document,  organized  in a special structure optimized for fast access
-   and  lookup. Each entry could be labelled to reflect its importance in
-   document.
-
-   tsquery  is  a  data  type for textual queries with support of boolean
-   operators.  It  consists of lexemes (optionally labelled) with boolean
-   operators between.
-
-   Table driven configuration allows to specify:
-     * parser, which used to break document onto lexemes
-     * what lexemes to index and the way they are processed
-     * dictionaries to be used along with stop words recognition.
-
-OpenFTS vs Tsearch2
-
-   [3]OpenFTS  is  a middleware between application and database. OpenFTS
-   uses  tsearch2  as  a  storage and database engine as a query executor
-   (searching).   Everything  else,  i.e.  parsing  of  documents,  query
-   processing, linguistics, carry outs on client side. That's why OpenFTS
-   has  its own configuration table (fts_conf) and works with its own set
-   of dictionaries. OpenFTS is more flexible, because it could be used in
-   multi-server  architecture  with  separate  machines for repository of
-   documents  (documents  could  be  stored  in filesystem), database and
-   query engine.
-
-   See [4]Documentation Roadmap for links to documentation.
-
-Authors
-
-     * Oleg Bartunov <oleg@sai.msu.su>, Moscow, Moscow University, Russia
-     * Teodor Sigaev <teodor@sigaev.ru>, Moscow,Moscow University,Russia
-
-Contributors
-
-     * Robert   John   Shepherd   and   Andrew   J.   Kopciuch  submitted
-       "Introduction  to  tsearch" (Robert - tsearch v1, Andrew - tsearch
-       v2)
-     * Brandon   Craig   Rhodes  wrote  "Tsearch2  Guide"  and  "Tsearch2
-       Reference" and proposed new naming convention for tsearch V2
-
-Sponsors
-
-     * ABC Startsiden - compound words support
-     * University of Mannheim for UTF-8 support (in 8.2)
-     * jfg:networks ([5]http:www.jfg-networks.com/) for Gin - Generalized
-       Inverted index (in 8.2)
-     * Georgia  Public  Library  Service  and LibLime, Inc. for Thesaurus
-       dictionary
-     * PostGIS community - GiST Concurrency and Recovery
-
-   The  authors are grateful to the Russian Foundation for Basic Research
-   and Delta-Soft Ltd., Moscow, Russia for support.
-
-Limitations
-
-     * Length of lexeme < 2K
-     * Length of tsvector (lexemes + positions) < 1Mb
-     * The number of lexemes < 4^32
-     * 0< Positional information < 16383
-     * No more than 256 positions per lexeme
-     * The number of nodes ( lexemes + operations) in tsquery < 32768
-
-References
-
-     * GiST development site -
-       [6]http://www.sai.msu.su/~megera/postgres/gist
-     * GiN development - [7]http://www.sigaev.ru/gin/
-     * OpenFTS home page - [8]http://openfts.sourceforge.net/
-     * Mailing list -
-       [9]http://sourceforge.net/mailarchive/forum.php?forum=openfts-gene
-       ral
-
-Documentation Roadmap
-
-     * Several docs are available from docs/ subdirectory
-          + "Tsearch V2 Introduction" by Andrew Kopciuch
-          + "Tsearch2 Guide" by Brandon Rhodes
-          + "Tsearch2 Reference" by Brandon Rhodes
-     * Readme.gendict in gendict/ subdirectory
-          + Also, check [10]Gendict tutorial
-     * Check [11]tsearch2 Wiki pages for various documentation
-
-Support
-
-   Authors  urgently  recommend  people  to  use  [12]openfts-general  or
-   [13]pgsql-general mailing lists for questions and discussions.
-
-Development History
-
-   Latest news
-
-   To the PostgreSQL 8.2 release we added:
-     * multibyte (UTF-8) support
-     * Thesaurus dictionary
-     * Query rewriting
-     * rank_cd  relevation  function  now  support  different  weights of
-       lexemes
-     * GiN support adds scalability of tsearch2
-
-   Pre-tsearch era
-          Development  of  OpenFTS  began in 2000 after realizing that we
-          need  a  search engine optimized for online updates with access
-          to  metadata  from  the  database. This is essential for online
-          news agencies, web portals, digital libraries, etc. Most search
-          engines  available utilize an inverted index which is very fast
-          for  searching  but  very  slow for online updates. Incremental
-          updates  of  an  inverted  index  is a complex engineering task
-          while  we  needed something light, free and with the ability to
-          access  metadata  from  the  database. The last requirement was
-          very important because in a real life application search engine
-          should  always  consult  metadata  (  topic,  permissions, date
-          range,  version,  etc.).  We  extensively  use  PostgreSQL as a
-          database  backend and have no intention to move from it, so the
-          problem  was  to find a data structure and a fast way to access
-          it.  PostgreSQL  has  rather  unique data type for storing sets
-          (think  about  words) - arrays, but lacks index access to them.
-          During our research we found a paper of Joseph Hellerstein, who
-          introduced  an  interesting  data structure suitable for sets -
-          RD-tree  (Russian  Doll  tree). Further research lead us to the
-          idea to use GiST for implementing RD-tree, but at that time the
-          GiST  code  was untouched for a long time and contained several
-          bugs.  After  work  on  improving  GiST  for  version  7.0.3 of
-          PostgreSQL  was done, we were able to implement RD-Tree and use
-          it  for index access to arrays of integers. This implementation
-          was  ideally  suited  for  small  arrays and eliminated complex
-          joins,  but  was practically useless for indexing large arrays.
-          The  next improvement came from an idea to represent a document
-          by  a  single bit-signature, a so-called superimposed signature
-          (see "Index Structures for Databases Containing Data Items with
-          Set-valued  Attributes",  1997,  Sven  Helmer  for details). We
-          developed  the  contrib/intarray  module and used it for full
-          text indexing.
-
-   tsearch v1
-          It was inconvenient to use integer id's instead of words, so we
-          introduced  a new data type called 'txtidx' - a searchable data
-          type  (textual)  with  indexed access. This was a first step of
-          our  work  on  an  implementation of a built-in PostgreSQL full
-          text search engine. Even though tsearch v1 had many features of
-          a  search  engine it lacked configuration support and relevance
-          ranking.  People were encouraged to use OpenFTS, which provided
-          relevance  ranking based on positional information and flexible
-          configuration.  OpenFTS  v.0.34  is  the  last version based on
-          tsearch v1.
-
-   tsearch V2
-          People  recognized  tsearch  as  a  powerful tool for full text
-          searching  and  insisted  on  adding  ranking  support,  better
-          configurability,  etc.  We already thought about moving most of
-          the  features  of  OpenFTS to tsearch, and in the early 2003 we
-          decided  to  work  on  a  new  version of tsearch. We abandoned
-          auxiliary  index  tables  which  were  used by OpenFTS to store
-          positional  information  and  modified the txtidx type to store
-          them  internally.  We added table-driven configuration, support
-          of  ispell  dictionaries,  snowball stemmers and the ability to
-          specify  which types of lexemes to index. Now, it's possible to
-          generate  headlines of documents with highlighted search terms.
-          These  changes make tsearch more user friendly and turn it into
-          a  really  powerful  full  text  search  engine. Brandon Rhodes
-          proposed  to  rename  tsearch  functions for consistency and we
-          renamed  txtidx  type  to tsvector and other things as well. To
-          allow  users  of tsearch v1 smooth upgrade, we named the module
-          as tsearch2. Since version 0.35 OpenFTS uses tsearch2.
-
-References
-
-   1. http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/docs/Tsearch_V2_Readme.html
-   2. http://snowball.tartarus.org/
-   3. http://openfts.sourceforge.net/
-   4. file://localhost/u/megera/WWW/postgres/gist/tsearch/V2/docs/Tsearch_V2_Readme82.html#dm
-   5. http:www.jfg-networks.com/
-   6. http://www.sai.msu.su/~megera/postgres/gist
-   7. http://www.sigaev.ru/gin/
-   8. http://openfts.sourceforge.net/
-   9. http://sourceforge.net/mailarchive/forum.php?forum=openfts-general
-  10. http://www.sai.msu.su/~megera/wiki/Gendict
-  11. http://www.sai.msu.su/~megera/wiki/Tsearch2
-  12. http://sourceforge.net/mailarchive/forum.php?forum=openfts-general
-  13. http://archives.postgresql.org/pgsql-general/