Fixes to RDB$SQL package.

Author: asfernandes

doc/sql.extensions/README.sql_package.md

@@ -19,24 +19,24 @@ Output parameters:
 - `LEVEL` type `INTEGER NOT NULL` - indentation level (may have gaps in relation to parent's level)
 - `PACKAGE_NAME` type `RDB$PACKAGE_NAME` - package name of a stored procedure
 - `OBJECT_NAME` type `RDB$RELATION_NAME` - object (table, procedure) name
-- `ALIAS` type `RDB$RELATION_NAME` - alias name
+- `ALIAS` type `RDB$SHORT_DESCRIPTION` - alias name
 - `RECORD_LENGTH` type `INTEGER` - record length for the record source
 - `KEY_LENGTH` type `INTEGER` - key length for the record source
-- `ACCESS_PATH` type `VARCHAR(255) CHARACTER SET UTF8 NOT NULL` - friendly plan description
+- `ACCESS_PATH` type `RDB$DESCRIPTION NOT NULL` - friendly plan description
 
 ```
 select *
-  from rdb$sql.explain('select * from employees where id = ?');
+  from rdb$sql.explain('select * from employee where emp_no = ?');
 ```
 
 ```
 select *
   from rdb$sql.explain(q'{
     select *
     from (
-      select name from employees
+      select full_name name from employee
       union all
-      select name from customers
+      select customer name from customer
     )
     where name = ?
   }');

src/jrd/sys-packages/SqlPackage.cpp

@@ -184,9 +184,9 @@ SqlPackage::SqlPackage(MemoryPool& pool)
 					{"PARENT_RECORD_SOURCE_ID", fld_gen_val, true},
 					{"LEVEL", fld_integer, false},
 					{"OBJECT_TYPE", fld_obj_type, true},
-					{"PACKAGE_NAME", fld_r_name, true},
+					{"PACKAGE_NAME", fld_pkg_name, true},
 					{"OBJECT_NAME", fld_r_name, true},
-					{"ALIAS", fld_r_name, true},
+					{"ALIAS", fld_short_description, true},
 					{"CARDINALITY", fld_statistics, true},
 					{"RECORD_LENGTH", fld_integer, true},
 					{"KEY_LENGTH", fld_integer, true},

src/jrd/sys-packages/SqlPackage.h

@@ -52,7 +52,7 @@ class SqlPackage final : public SystemPackage
 		(FB_SMALLINT, objectType)
 		(FB_INTL_VARCHAR(METADATA_IDENTIFIER_CHAR_LEN * METADATA_BYTES_PER_CHAR, CS_METADATA), packageName)
 		(FB_INTL_VARCHAR(METADATA_IDENTIFIER_CHAR_LEN * METADATA_BYTES_PER_CHAR, CS_METADATA), objectName)
-		(FB_INTL_VARCHAR(METADATA_IDENTIFIER_CHAR_LEN * METADATA_BYTES_PER_CHAR, CS_METADATA), alias)
+		(FB_INTL_VARCHAR(255 * METADATA_BYTES_PER_CHAR, CS_METADATA), alias)
 		(FB_DOUBLE, cardinality)
 		(FB_INTEGER, recordLength)
 		(FB_INTEGER, keyLength)