Commands

    rem  Some simple SELECTs
    select * from _col1;
    select rid, rownum, tname, colname from _col1;
    select count(*) from _col1;
    select ecount(*) from _col1;

    rem  SELECTs with WHERE, perl and SQL style.
    select * from _tab1 where tname =~ m/col/;
    select * from _tab1 where tid < 5;
    select * from _tab1 where numcols > 3 AND numcols < 6;

    rem basic joins
    select * from _tab1, _col1  where _tab1.tid = _col1.tid 
     and _tab1.tname =~ m/col/;

    rem  Column aliases and Expressions
    select tid as Table_ID, tname Name, (tid+1)/2 from _tab1;

    rem  Basic INSERT
    insert into test1 values ('a','b','c','d');
    insert into test1(col2, col1) values ('a','b','c','d');

    rem CREATE TABLE and INSERT...SELECT
    create table test2(col1 char, col2 char);
    insert into test2 (col1) select col1 from test1;

    rem  DELETE with WHERE
    delete from test1 where col1 < 'bravo' and col2 > 5;

    rem  UPDATE with WHERE (no subqueries supported)
    update test2 set col2 = 'foo' where col2 is null;

    rem CREATE an INDEX
    create index test1_ix on test1(col1);

    rem ADD a CHECK CONSTRAINT
    alter table test2 add constraint t2_cn1 check (col2 =~ m/(a|b|c|d)/x );

    commit

Genezzo also supports the following "short" commands: ct, dt, s, i, d, u

ct - create table

  example: ct EMP NAME=c ID=n
  SQL equivalent: CREATE TABLE EMP (NAME CHAR(10), ID NUMBER) ;
    

dt - drop table

  example: dt EMP
  SQL equivalent: DROP TABLE EMP ;
    

s - select

  example: s EMP *
  SQL equivalent: SELECT * FROM EMP ;

  example: s EMP rid rownum *
  SQL equivalent: SELECT ROWID, ROWNUM, * FROM EMP ;

  example: s EMP NAME
  SQL equivalent: SELECT NAME FROM EMP ;
    

i - insert

  example: i EMP bob 1 orville 2
  SQL equivalent: 
    INSERT INTO EMP VALUES ('bob', '1');
    INSERT INTO EMP VALUES ('orville', '2');
    

d, u - delete and update

  DELETE and UPDATE only work by rid 
  -- you cannot specify a predicate.

  example: d emp 1.2.3
  SQL equivalent: DELETE FROM EMP WHERE RID='1.2.3' ;

  example: u emp 1.2.3 wilbur 4
  SQL equivalent: UPDATE EMP SET NAME='wilbur', 
                                 ID='4' WHERE RID='1.2.3' ;
    

Genezzo stores information in a couple of subsidiary files: the default install creates a file called default.dbf which contains the basic dictionary information. Other data files can be added as needed. While the default configuration uses a single, fixed-size datafile, Genezzo can be configured to use datafiles that grow to some maximum size, and it can also be configured to automatically create new datafiles as necessary.

All tables are currently created in the system tablespace by default.

There are a couple of other useful commands:

HELP -- give help

DUMP -- dump out internal data structures

DUMP TABLES - list all tables

DUMP TS - dump tablespace information

RELOAD - reload all Genezzo perl modules (will lose uncommited changes, though)

COMMIT - force write of changes to database. Note that even CREATE TABLE is transactional -- you have to commit to update the persistent dictionary. Forgetting to commit can cause weird behaviors, since the buffer cache may flush data out to the dbf file. Then you can have the condition where the tablespace reuses these "empty" blocks and they already have data in them.

Environment