Below you will see the stored procedure that causes locks in Oracle 11. I am unfortunately in a corporate environment that doesn't allow me access to trace logs, or basically anything. So I've read tons of recommendations for how to do that, and cry that I can't do it. I'm not sure you can even determine from below if this would be the culprit. Anyway, thanks for everyone's time.
MERGE INTO my_owner.my_table tgtT
USING (SELECT diTT, sisCd FROM my_owner.NGR_DMNSN_TYP
where DMNSN_NM_TXT = 'myname'
and sisCd = 'RefDB') srcT
ON ( TGTT.diTT = srcT.diTT and TGTT.ID_TXT = 50000 )
WHEN MATCHED
THEN UPDATE SET TGTT.DSCRPTN_TXT = 'dfdf', TGTT.NM_TXT = 'bldfdfah'
WHEN NOT MATCHED
THEN
INSERT (TGTT.DSCRPTN_TXT, TGTT.NM_TXT, TGTT.diTT, TGTT.ID_NBR, TGTT.ID_TXT)
VALUES ('ee', 'ee', srcT.diTT, 50000, '50000' );
Related
I am trying to connect to Snowflake using R in databricks, my connection works and I can make queries and retrieve data successfully, however my problem is that it can take more than 25 minutes to simply connect, but once connected all my queries are quick thereafter.
I am using the sparklyr function 'spark_read_source', which looks like this:
query<- spark_read_source(
sc = sc,
name = "query_tbl",
memory = FALSE,
overwrite = TRUE,
source = "snowflake",
options = append(sf_options, client_Q)
)
where 'sf_options' are a list of connection parameters which look similar to this;
sf_options <- list(
sfUrl = "https://<my_account>.snowflakecomputing.com",
sfUser = "<my_user>",
sfPassword = "<my_pass>",
sfDatabase = "<my_database>",
sfSchema = "<my_schema>",
sfWarehouse = "<my_warehouse>",
sfRole = "<my_role>"
)
and my query is a string appended to the 'options' arguement e.g.
client_Q <- 'SELECT * FROM <my_database>.<my_schema>.<my_table>'
I can't understand why it is taking so long, if I run the same query from RStudio using a local spark instance and 'dbGetQuery', it is instant.
Is spark_read_source the problem? Is it an issue between Snowflake and Databricks? Or something else? Any help would be great. Thanks.
So.. I've been coding to make a GUI show the quantity of currency of a player, the datastore API works perfectly but the local script doesn't (it's local because else it would just update it each time a player's currency gets updated and would be a mess being the opposite of what I want to)
and well... sometimes it loads the currency into the GUI but other times it just stays on the original text: "Label" instead of my current currency (4600)
here's the proof
What normally happens and should always happen
What sometimes happens and shouldn't happen:
here's the script, I've tried putting waits on the start but the original code is inside the while true do..
wait(game.Players.LocalPlayer:WaitForChild("Data")
wait(game.Players.LocalPlayer.Data:WaitForChild("Bells"))
while true do
script.Parent.TextLabel.Text = game.Players.LocalPlayer:WaitForChild("Data"):WaitForChild("Bells").Value
wait() --wait is for not making the loop break and stop the whole script
end
well.. if you want to see if data is really in the player, here's the script, it requires a API (DataStore2)
--[Animal Crossing Roblox Edition Data Store]--
--Bryan99354--
--Module not mine--
--Made with a AlvinBlox tutorial--
--·.·.*[Get Data Store, do not erase]*.·.·--
local DataStore2 = require(1936396537)
--[Default Values]--
local DefaultValue_Bells = 300
local DefaultValue_CustomClothes = 0
--[Data Store Functions]--
game.Players.PlayerAdded:Connect(function(player)
--[Data stores]--
local BellsDataStore = DataStore2("Bells",player)
local Data = Instance.new("Folder",player)
Data.Name = "Data"
Bells = Instance.new("IntValue",Data)
Bells.Name = "Bells"
local CustomClothesDataStore = DataStore2("CustomClothes",player)
local CustomClothes = Instance.new("IntValue",Data)
CustomClothes.Name = "CustomClothes"
local function CustomClothesUpdate(UpdatedValue)
CustomClothes.Value = CustomClothesDataStore:Get(UpdatedValue)
end
local function BellsUpdate(UpdatedValue)
Bells.Value = BellsDataStore:Get(UpdatedValue)
end
BellsUpdate(DefaultValue_Bells)
CustomClothesUpdate(DefaultValue_CustomClothes)
BellsDataStore:OnUpdate(BellsUpdate)
CustomClothesDataStore:OnUpdate(CustomClothesUpdate)
end)
--[test and reference functions]--
workspace.TestDevPointGiver.ClickDetector.MouseClick:Connect(function(player)
local BellsDataStore = DataStore2("Bells",player)
BellsDataStore:Increment(50,DefaultValue_Bells)
end)
workspace.TestDevCustomClothesGiver.ClickDetector.MouseClick:Connect(function(player)
local CustomClothesDataStore = DataStore2("CustomClothes",player)
CustomClothesDataStore:Increment(50,DefaultValue_CustomClothes)
end)
the code that creates "Data" and "Bells" is located in the comment: Data Stores
the only script that gets the issue is the short one with no reason :<
I hope that you can help me :3
#Night94 I tryed your script but it also failed sometimes
The syntax in your LocalScript is a little off with the waits. With that fixed, it works every time. Also, I would use an event handler instead of updating the value with a loop:
game.Players.LocalPlayer:WaitForChild("Data"):WaitForChild("Bells").Changed:Connect(function(value)
script.Parent.TextLabel.Text = value
end)
I'm migrating a legacy application using DB2 iSeries on AS400 that has a specific behavior that I have to reproduce using .NET and DB2.Data.DB2.iSeries client for .NET.
What I'm describing works for me with DB2 non AS400 but in AS400 DB2 it worlks for the legacy application i'm replacing - but not with my application.
The behavior in the original application:
Begin Transaction
ExecuteReader () => Select col1 from table1 where col1 = 1 for update.
The row is now locked. anyone else who tries to run Select for update should fail.
Close the Reader opened in line 2.
The row is now unlocked. - anyone else who tried to run select for update should succeed.
Close transaction and live happily ever after.
In my .NET code I have two problems:
Step 2 - only checks if the row is already locked - but doesn't actually lock it. so another user can and does run select for update - WRONG BEHAVIOUR
Once that works - I need the lock to get unlocked when the reader is closed (step 4)
Here's my code:
var cb = new IBM.Data.DB2.iSeries.iDB2ConnectionStringBuilder();
cb.DataSource = "10.0.0.1";
cb.UserID = "User";
cb.Password = "Password";
using (var con = new IBM.Data.DB2.iSeries.iDB2Connection(cb.ToString()))
{
con.Open();
var t = con.BeginTransaction(System.Data.IsolationLevel.ReadUncommitted);
using (var c = con.CreateCommand())
{
c.Transaction = t;
c.CommandText = "select col1 from table1 where col1=1 FOR UPDATE";
using (var r = c.ExecuteReader())
{
while (r.Read()) {
MessageBox.Show(con.JobName + "The Row Should Be Locked");
}
}
MessageBox.Show(con.JobName + "The Row Should Be unlocked");
}
}
When you run this code twice - you'll see both processes reach the "This row should be locked" which is the problem I'm describing.
The desired result would be that the first process will reach the "This row should be locked" and that the second process will fail with resource busy error.
Then when the first process reaches the second message box - "the row should be unlocked" the second process( after running again ) will reach the "This row should be locked" message.
Any help would be greatly appreciated
The documentation says:
When the UPDATE clause is used, FETCH operations referencing the cursor acquire an exclusive row lock.
This implies a cursor is being used, and the lock occurs when the fetch statement is executed. I don't see a cursor, or a fetch in your code.
Now, whether .NET handles this as a cursor, I don't know, but the DB2 UDB documentation does not have this notation.
Isolation Level allows this behavior. Reading rows that are locked.
ReadUncommitted
A dirty read is possible, meaning that no shared locks are issued and no exclusive locks are honored.
After much investigations we created a work around in the form of a stored procedure that performs the lock for us.
The stored procedure looks like this:
CREATE PROCEDURE lib.Select_For_Update (IN SQL CHARACTER (5000) )
MODIFIES SQL DATA CONCURRENT ACCESS RESOLUTION WAIT FOR OUTCOME
DYNAMIC RESULT SETS 1 OLD SAVEPOINT LEVEL COMMIT ON RETURN
NO DISALLOW DEBUG MODE SET OPTION COMMIT = *CHG BEGIN
DECLARE X CURSOR WITH RETURN TO CLIENT FOR SS ;
PREPARE SS FROM SQL ;
OPEN X ;
END
Then we call it using:
var cb = new IBM.Data.DB2.iSeries.iDB2ConnectionStringBuilder();
cb.DataSource = "10.0.0.1";
cb.UserID = "User";
cb.Password = "Password";
using (var con = new IBM.Data.DB2.iSeries.iDB2Connection(cb.ToString()))
{
con.Open();
var t = con.BeginTransaction(System.Data.IsolationLevel.ReadUncommitted);
using (var c = con.CreateCommand())
{
c.Transaction = t;
c.CommandType = CommandType.StoredProcedure;
c.AddParameter("sql","select col1 from table1 where col1=1 FOR UPDATE");
c.CommandText = "lib.Select_For_Update"
using (var r = c.ExecuteReader())
{
while (r.Read()) {
MessageBox.Show(con.JobName + "The Row Should Be Locked");
}
}
MessageBox.Show(con.JobName + "The Row Should Be unlocked");
}
}
We don't like it - but it works.
I'm using Airflow for some ETL things and in some stages, I would like to use temporary tables (mostly to keep the code and data objects self-contained and to avoid to use a lot of metadata tables).
Using the Postgres connection in Airflow and the "PostgresOperator" the behaviour that I found was: For each execution of a PostgresOperator we have a new connection (or session, you name it) in the database. In other words: We lose all temporary objects of the previous component of the DAG.
To emulate a simple example, I use this code (do not run, just see the objects):
import os
from airflow import DAG
from airflow.operators.postgres_operator import PostgresOperator
default_args = {
'owner': 'airflow'
,'depends_on_past': False
,'start_date': datetime(2018, 6, 13)
,'retries': 3
,'retry_delay': timedelta(minutes=5)
}
dag = DAG(
'refresh_views'
, default_args=default_args)
# Create database workflow
drop_exist_temporary_view = "DROP TABLE IF EXISTS temporary_table_to_be_used;"
create_temporary_view = """
CREATE TEMPORARY TABLE temporary_table_to_be_used AS
SELECT relname AS views
,CASE WHEN relispopulated = 'true' THEN 1 ELSE 0 END AS relispopulated
,CAST(reltuples AS INT) AS reltuples
FROM pg_class
WHERE relname = 'some_view'
ORDER BY reltuples ASC;"""
use_temporary_view = """
DO $$
DECLARE
is_correct integer := (SELECT relispopulated FROM temporary_table_to_be_used WHERE views LIKE '%<<some_name>>%');
BEGIN
start_time := clock_timestamp();
IF is_materialized = 0 THEN
EXECUTE 'REFRESH MATERIALIZED VIEW ' || view_to_refresh || ' WITH DATA;';
ELSE
EXECUTE 'REFRESH MATERIALIZED VIEW CONCURRENTLY ' || view_to_refresh || ' WITH DATA;';
END IF;
END;
$$ LANGUAGE plpgsql;
"""
# Objects to be executed
drop_exist_temporary_view = PostgresOperator(
task_id='drop_exist_temporary_view',
sql=drop_exist_temporary_view,
postgres_conn_id='dwh_staging',
dag=dag)
create_temporary_view = PostgresOperator(
task_id='create_temporary_view',
sql=create_temporary_view,
postgres_conn_id='dwh_staging',
dag=dag)
use_temporary_view = PostgresOperator(
task_id='use_temporary_view',
sql=use_temporary_view,
postgres_conn_id='dwh_staging',
dag=dag)
# Data workflow
drop_exist_temporary_view >> create_temporary_view >> use_temporary_view
At the end of execution, I receive the following message:
[2018-06-14 15:26:44,807] {base_task_runner.py:95} INFO - Subtask: psycopg2.ProgrammingError: relation "temporary_table_to_be_used" does not exist
Someone knows if Airflow has some way to retain the same connection to the database? I think it can save a lot of work in creating/maintaining several objects in the database.
You can retain the connection to the database by building a custom Operator which leverages the PostgresHook to retain a connection to the db while you perform some set of sql operations.
You may find some examples in contrib on incubator-airflow or in Airflow-Plugins.
Another option is to persist this temporary data to XCOMs. This will give you the ability to keep the metadata used with the task in which it was created. This may help troubleshooting down the road.
I have my query on VB6 which was:
Set Db = DBEngine.OpenDatabase(App.Path & "\sample4nC4.mdb")
Set rs = Db.OpenRecordset("select *from tbl_student;")
Do Until rs.EOF
With ListView1
.ListItems.Add , , rs.Fields("stud_ID")
.ListItems(ListView.ListItems.Count).SubItems(1) = rs.Fields("stud_fname")
.ListItems(ListView1.ListItems.Count).SubItems(2) = rs.Fields("stud_lname")
.ListItems(ListView1.ListItems.Count).SubItems(3) = rs.Fields("stud_address")
.ListItems(ListView1.ListItems.Count).SubItems(4) = rs.Fields("stud_age")
End With
rs.MoveNext
Loop
When I execute this query, there was an error on line 2 says:
Run Time Error '13' Type Mismatch
I really don't get it because when I check the table name, it was correct and yet I cant access the table. Can anybody answer my problem?
Do you have references to ADO and DAO in your project?
If so, look at this Microsoft support article: https://support.microsoft.com/en-us/kb/181542
Do these
Replace your query from 'select *from tbl_student;'
to
'select stud_fname, stud_lname, stud_address, stud_age from tbl_student'
This includes (1. space between '' and 'from' 2. remove ';' 3. specify the field names explicitly)*
Put a breakpoint in the first line your program and step into, if it still fails check which line it's failing.