Sample for using stream

Download Sample Data

Download the sample data as follows.

## ##  1. Clone the sample data from MACHBASE git repository.
$ git clone https://github.com/MACHBASE/TagTutorial.git MyTutorial
 
## ##  2. Unzip the data you need.
$ cd MyTutorial/
$ gunzip edu_3_plc_stream/*.gz
 
## ##  3. Move to the directory where the sample data exist.
$ cd edu_3_plc_stream/

Create TAG, LOG Table

To use the STREAM feature, adjust the following commands to your environment and run them to create the TAG and LOG tables.

$ pwd
~/MyTutorial/edu_3_plc_stream
 
## ##  1-1. Create TAG table
$ machsql --server=127.0.0.1 --port=${MACHBASE_PORT_NO} --user=SYS --password=MANAGER --script=1_create_tag.sql
## ##  1-2. Load TAG Meta
$ sh 2_load_meta.sh
 
## ##  2. Create LOG table
$ machsql --server=127.0.0.1 --port=${MACHBASE_PORT_NO} --user=SYS --password=MANAGER --script=3_create_plc_tag_table.sql

Create and Run STREAM

Run the sample script written for the TAG and LOG tables you created. It creates and starts the STREAMs.

$ machsql --server=127.0.0.1 --port=${MACHBASE_PORT_NO} --user=SYS --password=MANAGER --script=4_plc_stream_tag.sql

The sample file contains two types of queries: one creates a STREAM and the other starts it.

## ##  Create STREAM Query Example
EXEC STREAM_CREATE(event_v0, 'insert into tag select ''MTAG_V00'', tm, v0 from plc_tag_table;');

## ##  Run STREAM Query Example
EXEC STREAM_START(event_v0);

Once the STREAMs are running, every time data is inserted into plc_tag_table, each STREAM runs and inserts that data into the TAG table.

Check STREAM Status

With v$streams, a virtual table provided by Machbase, you can check the number of running streams, the queries they use, their status, and error messages.

Mach> desc v$streams;
[ COLUMN ]
----------------------------------------------------------------------------------------------------
NAME                                                        NULL?    TYPE                LENGTH
----------------------------------------------------------------------------------------------------
NAME                                                                 varchar             100
LAST_EX_TIME                                                         datetime            31
TABLE_NAME                                                           varchar             100
END_RID                                                              long                20
STATE                                                                varchar             10
QUERY_TXT                                                            varchar             2048
ERROR_MSG                                                            varchar             2048
FREQUENCY                                                            ulong               20

You can check the status of all STREAMs as follows.

Mach> select state, name, table_name, query_txt from v$streams;
STATE   NAME     TABLE_NAME    QUERY_TXT
------------------------------------------------------------------------------------------------
RUNNING EVENT_V0 PLC_TAG_TABLE insert into tag select 'MTAG_V00', tm, v0 from plc_tag_table;
RUNNING EVENT_V1 PLC_TAG_TABLE insert into tag select 'MTAG_V00', tm, v1 from plc_tag_table;
RUNNING EVENT_C0 PLC_TAG_TABLE insert into tag select 'MTAG_C00', tm, c0 from plc_tag_table;
RUNNING EVENT_C1 PLC_TAG_TABLE insert into tag select 'MTAG_C01', tm, c1 from plc_tag_table;
RUNNING EVENT_C2 PLC_TAG_TABLE insert into tag select 'MTAG_C02', tm, c2 from plc_tag_table;
RUNNING EVENT_C3 PLC_TAG_TABLE insert into tag select 'MTAG_C03', tm, c3 from plc_tag_table;
RUNNING EVENT_C4 PLC_TAG_TABLE insert into tag select 'MTAG_C04', tm, c4 from plc_tag_table;
RUNNING EVENT_C5 PLC_TAG_TABLE insert into tag select 'MTAG_C05', tm, c5 from plc_tag_table;
RUNNING EVENT_C6 PLC_TAG_TABLE insert into tag select 'MTAG_C06', tm, c6 from plc_tag_table;
RUNNING EVENT_C7 PLC_TAG_TABLE insert into tag select 'MTAG_C07', tm, c7 from plc_tag_table;
RUNNING EVENT_C8 PLC_TAG_TABLE insert into tag select 'MTAG_C08', tm, c8 from plc_tag_table;
RUNNING EVENT_C9 PLC_TAG_TABLE insert into tag select 'MTAG_C09', tm, c9 from plc_tag_table;
RUNNING EVENT_C10 PLC_TAG_TABLE insert into tag select 'MTAG_C10', tm, c10 from plc_tag_table;
RUNNING EVENT_C11 PLC_TAG_TABLE insert into tag select 'MTAG_C11', tm, c11 from plc_tag_table;
RUNNING EVENT_C12 PLC_TAG_TABLE insert into tag select 'MTAG_C12', tm, c12 from plc_tag_table;
RUNNING EVENT_C13 PLC_TAG_TABLE insert into tag select 'MTAG_C13', tm, c13 from plc_tag_table;
RUNNING EVENT_C14 PLC_TAG_TABLE insert into tag select 'MTAG_C14', tm, c14 from plc_tag_table;
RUNNING EVENT_C15 PLC_TAG_TABLE insert into tag select 'MTAG_C15', tm, c15 from plc_tag_table;

Load Data

After confirming that all STREAMs are running, load data with machloader and check how the STREAMs work. Because a STREAM works regardless of the input method, data is automatically inserted into the TAG table whether you use CLI, JDBC, Collector, or another input method.

$ cat 5_plc_tag_load.sh
machloader -i -t plc_tag_table -d 5_plc_tag.csv -F "tm YYYY-MM-DD HH24:MI:SS mmm:uuu:nnn"
 
$ sh 5_plc_tag_load.sh
-----------------------------------------------------------------
     Machbase Data Import/Export Utility.
     Release Version 8.5.4.develop
     Copyright 2014 MACHBASE Corporation or its subsidiaries.
     All Rights Reserved.
-----------------------------------------------------------------
NLS            : US7ASCII            EXECUTE MODE   : IMPORT
TARGET TABLE   : plc_tag_table       DATA FILE      : 5_plc_tag.csv
IMPORT MODE    : APPEND              FIELD TERM     : ,
ROW TERM       : \n                  ENCLOSURE      : "
ESCAPE         : \                   ARRIVAL_TIME   : FALSE
ENCODING       : NONE                HEADER         : FALSE
CREATE TABLE   : FALSE              CREATE TABLESPACE: FALSE
 
 Progress bar                       Imported records        Error records
                                               80000                    0

If you query the TAG table while the data is loading, you can see the data being inserted in real time.

Mach> select count(*) from TAG;
count(*)
-----------------------
16775979
[1] row(s) selected.
Mach> select count(*) from TAG;
count(*)
-----------------------
17609187
[1] row(s) selected.
Mach> select count(*) from TAG;
count(*)
-----------------------
18238357
[1] row(s) selected.
Elapsed time: 0.000

Result of STREAM

You can check how far each STREAM has read the source table (plc_tag_table) as follows.

Mach> select name, state, end_rid from v$streams;
name      state   end_rid
---------------------------------------------------------
EVENT_V0  RUNNING 909912
EVENT_V1  RUNNING 1584671
EVENT_C0  RUNNING 1312416
EVENT_C1  RUNNING 1268520
EVENT_C2  RUNNING 1636800
EVENT_C3  RUNNING 1197840
EVENT_C4  RUNNING 622728
EVENT_C5  RUNNING 972780
EVENT_C6  RUNNING 1021512
EVENT_C7  RUNNING 1287474
EVENT_C8  RUNNING 826956
EVENT_C9  RUNNING 1639032
EVENT_C10 RUNNING 725954
EVENT_C11 RUNNING 1511436
EVENT_C12 RUNNING 531079
EVENT_C13 RUNNING 1004400
EVENT_C14 RUNNING 741768
EVENT_C15 RUNNING 746604
[18] row(s) selected.

If the end_rid value equals the number of records in the source table, there is no more data to read from the source table.

Mach> select name, state, end_rid from v$streams;
name      state   end_rid
---------------------------------------------------------
EVENT_V0  RUNNING 2000000
EVENT_V1  RUNNING 2000000
EVENT_C0  RUNNING 2000000
EVENT_C1  RUNNING 2000000
EVENT_C2  RUNNING 2000000
EVENT_C3  RUNNING 2000000
EVENT_C4  RUNNING 2000000
EVENT_C5  RUNNING 2000000
EVENT_C6  RUNNING 2000000
EVENT_C7  RUNNING 2000000
EVENT_C8  RUNNING 2000000
EVENT_C9  RUNNING 2000000
EVENT_C10 RUNNING 2000000
EVENT_C11 RUNNING 2000000
EVENT_C12 RUNNING 2000000
EVENT_C13 RUNNING 2000000
EVENT_C14 RUNNING 2000000
EVENT_C15 RUNNING 2000000
[18] row(s) selected.

The number of rows in the TAG table equals number of records in the source table × number of STREAMs, which confirms that the STREAMs have read all the data correctly.

Mach> select count(*) from TAG;
count(*)
-----------------------
36000000
[1] row(s) selected.

You can also check the time range of the loaded data as follows.

Mach> select min(time), max(time) from TAG;
min(time)                       max(time)
-------------------------------------------------------------------
2009-01-28 07:03:34 000:000:000 2009-01-28 12:36:58 020:000:000
[1] row(s) selected.

Add Data

Use an INSERT statement to check whether the STREAMs actually respond to each input.

Mach> insert into plc_tag_table values(TO_DATE('2009-01-28 12:37:00 000:000:000'), 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000, 50000);
1 row(s) inserted.

As soon as one record is added to PLC_TAG_TABLE, the end_rid of each stream increases to 2000001, as shown below.

Mach> select name, state, end_rid from v$streams;
name      state   end_rid
---------------------------------------------------------------
EVENT_V0  RUNNING 2000001
EVENT_V1  RUNNING 2000001
EVENT_C0  RUNNING 2000001
EVENT_C1  RUNNING 2000001
EVENT_C2  RUNNING 2000001
EVENT_C3  RUNNING 2000001
EVENT_C4  RUNNING 2000001
EVENT_C5  RUNNING 2000001
EVENT_C6  RUNNING 2000001
EVENT_C7  RUNNING 2000001
EVENT_C8  RUNNING 2000001
EVENT_C9  RUNNING 2000001
EVENT_C10 RUNNING 2000001
EVENT_C11 RUNNING 2000001
EVENT_C12 RUNNING 2000001
EVENT_C13 RUNNING 2000001
EVENT_C14 RUNNING 2000001
EVENT_C15 RUNNING 2000001
[18] row(s) selected.

Last updated on Sep 21, 2026

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