Q
Problem solve Get help with specific problems with your technologies, process and projects.

# Changing block size

## I'm moving from 8i (8K block size) to 9i (16K block size). What is the best uniform size to minimize wasted space?

I'm moving from 8i (8K block size) to 9i (16K block size).

1. What is the best uniform size to minimize wasted space for T1, T2, T3, T4, LARGE, MEDIUM and SMALL?
2. I would also like to keep number of extents under the LMT extent threshold (for 16K block size: 1024 / 2 = 512).
3. How do you determine what is ideal?

The first four tables are frequently accessed and I'd like to put each in its own tablespace.

```     BYTES      AVGROW  NUMROWs

T01  2934046720    351   6927068

T02  1357619200     40  25814396

T03  1305518080    186   4678146

T04   658841600     90   5380288

LARGE UNIFORM SZ ?

T05   293068800     31   5946303

T06   293068800     36   4567866

T06   182804480     23   4820931

T08   121978880     24   3196038

T09    82739200     31   1554056

T10    59023360     27   1474153

T11    50913280     27   1477840

MEDIUM UNIFORM SZ?

T12    17612800     53    264330

T13    17530880     64    183504

T14    15892480     37    359238

T15     6184960    135     36074

T16     5283840     32    104411

T17     3932160    196     15484

T18     3481600     32     83276

T19     1597440     29     45335

T20     1597440    127      9813

SMALL  UNIFORM SZ ?

T21      737280     28     19545

T22      286720     25      8158

T23      245760    278       677

T24       81920     35      1071

T25       81920     61       480

T26       81920     33       969

T27       40960     89       171

```
To change your block size, you are going to have to use Oracle's export and import utilities to perform your migration. So export your current Oracle 8i database to a dump file. Then recreate your database as a 9i database (or go straight to 10g if possible!) this time with a 16K block size.

After you have created your 9i database with the new block size, precreate your tablespaces to hold your data. When you create your tablespaces, make the Locally Managed Tablespaces and have Oracle automatically determine your extent sizes for you. The following is an example:

```CREATE TABLESPACE users
DATAFILE '/u01/orcl/users01.dbf' SIZE 100M EXTENT MANAGEMENT LOCAL AUTOALLOCATE;
```

When you use AUTOALLOCATE, Oracle will decide the best extent sizes for you. Since I've been using AUTOALLOCATE for a number of years now, I have not given one single thought to the optimal extent size for my database segments. I quit specifying my extent sizes years ago and have never looked back.

#### Have a question for an expert?

Get answers from a TechTarget expert on whatever's puzzling you.

You will be able to add details on the next page.

#### Start the conversation

Send me notifications when other members comment.

## SearchDataManagement

• ### ArangoDB 3.5 update improves multi-model database platform

ArangoDB 3.5 accelerates its database platform with improved query performance and enhanced data security capabilities, as market...

• ### GDPR, AI intensify privacy and data protection compliance demands

This guide covers the challenges data management teams face on data protection and privacy, particularly with the rise of GDPR ...

• ### SnapLogic boosts its data integration technology with AI

SnapLogic's latest update for its Intelligent Integration Platform aims to make it easier for users to benefit from data ...

• ### Museums and data: A powerful combination

With more and more museums using data to inform their decision-making processes, visitors are reaping the benefits by enjoying a ...

• ### 5 augmented analytics examples in the enterprise

Here are the top examples of augmented analytics uses that BI vendors support and enable, including data preparation, NLP-based ...

• ### Phocas BI tool proves its value for manufacturers, wholesalers

With its focus on the manufacturing and wholesale distribution industries, Phocas Software has carved out a niche for itself ...

## SearchSAP

• ### How to implement DevOps for SAP Cloud Platform: 4 best practices

A successful implementation of DevOps for SAP begins with understanding several best practices. Here are four to get you started.

• ### SAP S/4HANA Cloud 1908 gets more RPA, embedded analytics

The quarterly release of SAP S/4HANA Cloud includes new RPA and embedded analytics capabilities. One analyst was blunt about his ...

• ### Experts debate whether SAP acquisition of Qualtrics can deliver CX

Ten months after SAP paid \$8 billion for the SaaS experience management platform, experts still differ on what Qualtrics adds to ...

## SearchSQLServer

• ### SQL Server database design best practices and tips for DBAs

Good database design is a must to meet processing needs in SQL Server systems. In a webinar, consultant Koen Verbeeck offered ...

• ### SQL Server in Azure database choices and what they offer users

SQL Server databases can be moved to the Azure cloud in several different ways. Here's what you'll get from each of the options ...

• ### Using a LEFT OUTER JOIN vs. RIGHT OUTER JOIN in SQL

In this book excerpt, you'll learn LEFT OUTER JOIN vs. RIGHT OUTER JOIN techniques and find various examples for creating SQL ...

## TheServerSide.com

• ### Can a left shift in Java cause DevOps developer burnout?

DevOps burnout is more common than you think. Pay attention to the details in your Java shift left to make sure your dev and ...

• ### Microsoft gains instant Java credibility with jClarity buy

Microsoft has acquired jClarity to help optimize its Azure cloud platform to run Java workloads, a coveted target for the now ...

• ### How to install the JDK on Windows and set up JAVA_HOME

You have options when it comes to JDK installations on Windows and Linux. Here are some helpful tips to ensure a proper install ...

## SearchDataCenter

• ### Iran says it's building an AI supercomputer, despite sanctions

In a tweet, Iran said it is building a new supercomputer. Other nations are doing the same because high performance computing ...

• ### IBM Power chip instruction set now open source

IBM opened up its Power server Instruction Set Architecture allowing the open source community to develop more innovative ...

• ### Big Switch updates its Cloud-First Networking portfolio

Big Switch Networks' new products and features aim to help solve issues such as lack of operational consistency, visibility and ...

## SearchContentManagement

• ### Box Shield adds tighter controls for content sharing

New Box security features enable file- and folder-level access control, while admins and security staff get machine-learning ...

• ### Evergage launches Data Warehouse, a BI analytics product

Data Warehouse, Evergage's new BI analytics product, is designed to collect and analyze customer data in an effort to provide ...

• ### Upgrades to Nintex Forms simplifies electronic form creation

The new form designer by Nintex brings user-friendly capabilities to Nintex Forms for both electronic form creation and data ...

## SearchHRSoftware

• ### CEO commitment to upskilling employees may boost HR tech

Top CEOs are promising to train their employees and make sure they are ready for an automating world. Whether the promise is real...

• ### Employee engagement technology not a panacea for HR woes

Employee engagement comes in many shapes and forms, leaving employers to scratch their heads at the best way to motivate their ...

• ### Hiring vendor says gender-based AI bias is pervasive

Gender bias in AI algorithms for recruiting and hiring is a big problem, according to the head of Job.com. With a new hire, the ...

Close