fixed some issues in postgres full text search and transferred "deleted" info onto the thread objects

1 files changed, 304 insertions, 0 deletions

diff --git a/askbot/search/postgresql/thread_and_post_models_10032013.plsql b/askbot/search/postgresql/thread_and_post_models_10032013.plsql
new file mode 100644
index 00000000..72f17fea
--- /dev/null
+++ b/askbot/search/postgresql/thread_and_post_models_10032013.plsql
@@ -0,0 +1,304 @@
+/* function testing for existence of a column in a table
+   if table does not exists, function will return "false" */
+CREATE OR REPLACE FUNCTION column_exists(colname text, tablename text)
+RETURNS boolean AS 
+$$
+DECLARE
+    q text;
+    onerow record;
+BEGIN
+
+    q = 'SELECT attname FROM pg_attribute WHERE attrelid = ( SELECT oid FROM pg_class WHERE relname = '''||tablename||''') AND attname = '''||colname||''''; 
+
+    FOR onerow IN EXECUTE q LOOP
+        RETURN true;
+    END LOOP;
+
+    RETURN false;
+END;
+$$ LANGUAGE plpgsql;
+
+/* function adding tsvector column to table if it does not exists */
+CREATE OR REPLACE FUNCTION add_tsvector_column(colname text, tablename text)
+RETURNS boolean AS
+$$
+DECLARE
+    q text;
+BEGIN
+    IF NOT column_exists(colname, tablename) THEN
+        q = 'ALTER TABLE ' || tablename || ' ADD COLUMN ' || colname || ' tsvector';
+        EXECUTE q;
+        RETURN true;
+    ELSE
+        q = 'UPDATE ' || tablename || ' SET ' || colname || '=NULL';
+        EXECUTE q;
+        RETURN false;
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+/* aggregate function that concatenates tsvectors */
+CREATE OR REPLACE FUNCTION tsv_add(tsv1 tsvector, tsv2 tsvector)
+RETURNS tsvector AS
+$$
+BEGIN
+    RETURN tsv1 || tsv2;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION setup_aggregates() RETURNS boolean AS
+$$
+DECLARE
+    onerow record;
+BEGIN
+    FOR onerow IN SELECT * FROM pg_proc WHERE proname = 'concat_tsvectors' AND proisagg LOOP
+        DROP AGGREGATE concat_tsvectors(tsvector);
+    END LOOP;
+    CREATE AGGREGATE concat_tsvectors (
+        BASETYPE = tsvector,
+        SFUNC = tsv_add,
+        STYPE = tsvector,
+        INITCOND = ''
+    );
+    RETURN true;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT setup_aggregates();
+
+/* language name resolution function. todo: move languace conv to python code */
+DROP FUNCTION IF EXISTS get_language_name_from_code(lang_code text);
+CREATE OR REPLACE FUNCTION get_language_name_from_code(lang_code text)
+RETURNS regconfig AS
+$$
+BEGIN
+    IF lang_code = 'en' THEN
+        RETURN 'english';
+    ELSIF lang_code = 'da' THEN
+        RETURN 'danish';
+    ELSIF lang_code = 'nl' THEN
+        RETURN 'danish';
+    ELSIF lang_code = 'fi' THEN
+        RETURN 'finnish';
+    ELSIF lang_code = 'fr' THEN
+        RETURN 'french';
+    ELSIF lang_code = 'de' THEN
+        RETURN 'german';
+    ELSIF lang_code = 'hu' THEN
+        RETURN 'hungarian';
+    ELSIF lang_code = 'it' THEN
+        RETURN 'italian';
+    ELSIF lang_code = 'nb' THEN
+        RETURN 'norwegian';
+    ELSIF lang_code = 'pt' THEN
+        RETURN 'portugese';
+    ELSIF lang_code = 'ro' THEN
+        RETURN 'romanian';
+    ELSIF lang_code = 'ru' THEN
+        RETURN 'russian';
+    ELSIF lang_code = 'es' THEN
+        RETURN 'spanish';
+    ELSIF lang_code = 'sv' THEN
+        RETURN 'swedish';
+    ELSIF lang_code = 'tr' THEN
+        RETURN 'turkish';
+    ELSIF lang_code = 'ja' THEN
+        RETURN 'japanese';
+    END IF;
+    RETURN 'english';
+END;
+$$ LANGUAGE plpgsql;
+
+/* calculates text search vector for the individual thread row
+DOES not include question body post, answers or comments */
+DROP FUNCTION IF EXISTS get_thread_tsv(title text, tagnames text);
+CREATE OR REPLACE FUNCTION get_thread_tsv(title text, tagnames text, lang_code text)
+RETURNS tsvector AS
+$$
+DECLARE
+    lang_name regconfig;
+BEGIN
+    lang_name = get_language_name_from_code(lang_code);
+    /* todo add weight depending on votes */
+    RETURN  setweight(to_tsvector(lang_name, coalesce(title, '')), 'A') ||
+            setweight(to_tsvector(lang_name, coalesce(tagnames, '')), 'A');
+END;
+$$ LANGUAGE plpgsql;
+
+/* calculates text seanch vector for the individual question row */
+DROP FUNCTION IF EXISTS get_post_tsv(text text, post_type text);
+CREATE OR REPLACE FUNCTION get_post_tsv(text text, post_type text, lang_code text)
+RETURNS tsvector AS
+$$
+DECLARE
+    lang_name regconfig;
+BEGIN
+    /* todo adjust weights to reflect votes */
+    lang_name = get_language_name_from_code(lang_code);
+    IF post_type='question' THEN
+        RETURN setweight(to_tsvector(lang_name, coalesce(text, '')), 'B');
+    ELSIF post_type='answer' THEN
+        /* todo reflect whether the answer acepted or has many points */
+        RETURN setweight(to_tsvector(lang_name, coalesce(text, '')), 'C');
+    ELSIF post_type='comment' THEN
+        RETURN setweight(to_tsvector(lang_name, coalesce(text, '')), 'D');
+    ELSE
+        RETURN to_tsvector('');
+    END IF;
+END;
+$$ LANGUAGE plpgsql;
+
+/* calculates text search vector for the question body part by thread id
+here we extract question title and the text by thread_id and then
+calculate the text search vector. In the future question
+title will be moved to the askbot_thread table and this function
+will be simpler.
+*/
+CREATE OR REPLACE FUNCTION get_thread_question_tsv(thread_id integer, language_code text)
+RETURNS tsvector AS
+$$
+DECLARE
+    query text;
+    onerow record;
+BEGIN
+    query = 'SELECT text FROM askbot_post WHERE thread_id=' || thread_id ||
+            ' AND post_type=''question'' AND deleted=false';
+    FOR onerow in EXECUTE query LOOP
+        RETURN get_post_tsv(onerow.text, 'question', language_code);
+    END LOOP;
+    RETURN to_tsvector('');
+END;
+$$ LANGUAGE plpgsql;
+
+DROP FUNCTION IF EXISTS get_dependent_comments_tsv(object_id integer, tablename text);
+CREATE OR REPLACE FUNCTION get_dependent_comments_tsv(parent_id integer)
+RETURNS tsvector AS
+$$
+DECLARE
+    query text;
+    onerow record;
+BEGIN
+    query = 'SELECT concat_tsvectors(text_search_vector), count(*) FROM askbot_post' ||
+        ' WHERE parent_id=' || parent_id || 
+        ' AND post_type=''comment'' AND deleted=false';
+    FOR onerow IN EXECUTE query LOOP
+        IF onerow.count = 0 THEN
+            RETURN to_tsvector('');
+        ELSE
+            RETURN onerow.concat_tsvectors;
+        END IF;
+    END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+DROP FUNCTION IF EXISTS get_dependent_answers_tsv(question_id integer);
+CREATE OR REPLACE FUNCTION get_dependent_answers_tsv(thread_id integer, language_code text)
+RETURNS tsvector AS
+$$
+DECLARE
+    query text;
+    onerow record;
+BEGIN
+    query = 'SELECT concat_tsvectors(text_search_vector), count(*)' ||
+       'FROM askbot_post WHERE post_type = ''answer'' AND thread_id = ' || thread_id ||
+       ' AND deleted=false';
+    FOR onerow IN EXECUTE query LOOP
+        IF onerow.count = 0 THEN
+            RETURN to_tsvector('');
+        ELSE
+            RETURN onerow.concat_tsvectors;
+        END IF;
+    END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS thread_search_vector_update_trigger on askbot_thread;
+DROP TRIGGER IF EXISTS thread_search_vector_insert_trigger on askbot_thread;
+DROP TRIGGER IF EXISTS post_search_vector_update_trigger on askbot_post;
+
+/* create tsvector columns in the content tables
+ need to isolate these into own transactions, b/c of a weird mix
+ of triggers/update and alter table statements
+*/
+SELECT add_tsvector_column('text_search_vector', 'askbot_thread');
+COMMIT;
+BEGIN;
+SELECT add_tsvector_column('text_search_vector', 'askbot_post');
+COMMIT;
+BEGIN;
+SELECT add_tsvector_column('title_search_vector', 'askbot_thread');
+COMMIT;
+BEGIN;
+
+/* populate tsvectors with data */
+-- post tsvectors
+UPDATE askbot_post set text_search_vector = get_post_tsv(text, post_type, language_code) WHERE post_type IN ('answer', 'comment', 'question');
+UPDATE askbot_post as q SET text_search_vector = text_search_vector ||
+    get_dependent_comments_tsv(q.id) WHERE post_type IN ('question', 'answer');
+--thread tsvector
+UPDATE askbot_thread SET text_search_vector = get_thread_tsv(title, tagnames, language_code);
+UPDATE askbot_thread as t SET text_search_vector = text_search_vector ||
+    get_dependent_answers_tsv(t.id, t.language_code) ||
+    get_thread_question_tsv(t.id, t.language_code);
+UPDATE askbot_thread SET title_search_vector = get_thread_tsv(title, tagnames, language_code);
+
+/* one trigger per table for tsv updates */
+
+/* set up update triggers */
+CREATE OR REPLACE FUNCTION thread_update_trigger() RETURNS trigger AS
+$$
+DECLARE
+    title_tsv tsvector;
+BEGIN
+    title_tsv = get_thread_tsv(new.title, new.tagnames, new.language_code);
+    new.title_search_vector = title_tsv;
+    new.text_search_vector = new.text_search_vector || title_tsv;
+    RETURN new;
+END;
+$$ LANGUAGE plpgsql;
+CREATE TRIGGER thread_search_vector_update_trigger 
+BEFORE UPDATE ON askbot_thread FOR EACH ROW EXECUTE PROCEDURE thread_update_trigger();
+
+CREATE OR REPLACE FUNCTION thread_insert_trigger() RETURNS trigger AS
+$$
+BEGIN
+    new.text_search_vector = get_thread_tsv(new.title, new.tagnames, new.language_code);
+    new.title_search_vector = new.text_search_vector;
+    RETURN new;
+END;
+$$ LANGUAGE plpgsql;
+CREATE TRIGGER thread_search_vector_insert_trigger
+BEFORE INSERT ON askbot_thread FOR EACH ROW EXECUTE PROCEDURE thread_insert_trigger();
+
+/* post trigger */
+CREATE OR REPLACE FUNCTION post_trigger() RETURNS trigger AS
+$$
+BEGIN
+    IF new.post_type = 'question' OR new.post_type = 'answer' THEN
+        new.text_search_vector = get_post_tsv(
+                                        new.text,
+                                        new.post_type,
+                                        new.language_code
+                                    );
+        UPDATE askbot_thread SET text_search_vector=text_search_vector || 
+                                    new.text_search_vector WHERE id=new.thread_id;
+    ELSIF new.post_type = 'comment' THEN
+        new.text_search_vector = get_post_tsv(
+                                        new.text,
+                                        'comment',
+                                        new.language_code
+                                    );
+        UPDATE askbot_post SET text_search_vector=text_search_vector ||
+                                    new.text_search_vector WHERE id=new.parent_id;
+    END IF;
+    return new;
+END;
+$$ LANGUAGE plpgsql;
+CREATE TRIGGER post_search_vector_update_trigger 
+BEFORE INSERT OR UPDATE ON askbot_post FOR EACH ROW EXECUTE PROCEDURE post_trigger();
+
+COMMIT;
+BEGIN;
+
+DROP INDEX IF EXISTS askbot_search_idx;
+CREATE INDEX askbot_search_idx ON askbot_thread USING gin(text_search_vector);