How to find all objects that use dblinks
First
Create a temporary table as data of dictionary view ALL_VIEWS and convert column TEXT (view text) to CLOB type.
CREATE TABLE tmp_views AS SELECT Read more
Announcing Krush – idiomatic persistence layer for Kotlin, based on Exposed
We've released a persistence library for Kotlin, you can find it on our Github. It’s a JPA-to-Exposed SQL DSL generator. Read more
Clojure web development – state of the art – part 2
This is part 2 of my “Clojure web development” series. You can discuss first part on this reddit thread. After reading the comments I must Read more
Distributed scans with HBase
HBase is by design a columnar store, that is optimized for random reads. You just ask for a row using rowId as an identifier and you get your data instantaneously.
Performing a scan on part or whole table is a completely different thing. First of all, it is sequential. Meaning it is rather slow, because it doesn't use all the RegionServers at the same time. It is implemented that way to realize the contract of Scan command - which has to return results sorted by key.
So, how to do this efficiently?HBase is by design a columnar store, that is optimized for random reads. You just ask for a row using rowId as an identifier and you get your data instantaneously.
Performing a scan on part or whole table is a completely different thing. First of all, it is sequential. Meaning it is rather slow, because it doesn't use all the RegionServers at the same time. It is implemented that way to realize the contract of Scan command - which has to return results sorted by key.
So, how to do this efficiently? Read more
TouK about Orient DB in Cairo and about Type Driven Development in Bergen
Last month Maciek Próchniak spoke at two noteworthy conferences: Java Developers Conference in Cairo and Booster Conference in Bergen. Read more
Use XMLs not groovy scripts with db migration plugin!
I have 48 domain classes in my Grails 2.1 project and I use Grails Database Migration Plugin 1.2 for a database management. Recently I've noticed that it becomes terribly slow when running application, even if there are no changes to be applied. I swit... Read more
Indeksy na kolumnach z wartościami nullowymi cz. 2
Jest jeszcze jeden sposób indeksowania, który pozwala nam na bardzo wygodne korzystanie z indeksów i wyszukiwanie wartości nullowych. Mianowicie indeks jest prostym indeksem składającym się Read more
Indeksy na kolumnach z wartościami nullowymi cz. 1
A tak dokładnie aby zadziałał, gdy chcemy zrobić zapytanie:
select * from tablica where kolumna is null;
Zakładamy wtedy indeks funkcyjny:
create index kolumna_idx on Read more
Table viewer using JQuery plugin and JEE
DataTables is a JQuery plugin, facilitating building Ajax table editors. In this example, I show how to connect it to JEE backend, which is a Read more
Weird Oracle
“It’s not a bug, it’s a feature” PL/SQL like any other procedural extension to SQL has the ability to execute dynamic statements: EXECUTE IMMEDIATE. But Read more