Better indexing for string properties to support path-based lookups

- Normal prefix-index has been shortened to 32 chars (from 64)
 - Added a fully indexed 'string_end' column of 16 characters
 - iBatis queries are optimized to pull short strings from the index
 - Long paths and NodeRefs are well-indexed using this approach


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@15833 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

config/alfresco/dbscripts/create/3.2/org.hibernate.dialect.MySQLInnoDBDialect/AlfrescoPostCreate-3.2-PropertyValueTables.sql

@@ -45,8 +45,10 @@ CREATE TABLE alf_prop_double_value
 CREATE TABLE alf_prop_string_value
 (
    id BIGINT NOT NULL AUTO_INCREMENT,
-   string_value text NOT NULL,
-   INDEX idx_alf_prop_str_val (string_value(64)),
+   string_value TEXT NOT NULL,
+   string_end VARCHAR(16) NOT NULL,
+   INDEX idx_alf_prop_str_start (string_value(32)),
+   INDEX idx_alf_prop_str_end (string_end),
    PRIMARY KEY (id)
 ) ENGINE=InnoDB;