ByJoel Pérez ( Oracle ACE Director )

Oracle RAC now available on Docker..!!

Oracle RAC now available on Docker..!!

Now you have an opportunity to try RAC on Docker for yourself, as Oracle has just released Docker build files to create an Oracle RAC Database Docker image. Click the link down below to read about it.

Oracle RAC now available on Docker!

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

Live Demo: Oracle Autonomous Data Warehouse Cloud

Live Demo: Oracle Autonomous Data Warehouse Cloud

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

Oracle 18c: Your Autonomous Future: A Panel Discussion..!!

Oracle 18c: Your Autonomous Future: A Panel Discussion..!!

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

算法分析：Oracle 11g 中基于哈希算法对唯一值数(NDV)的估算

算法分析：Oracle 11g 中基于哈希算法对唯一值数(NDV)的估算

在这里阅读原文

字段的统计数据是 CBO 优化器估算执行计划代价的重要依据。而字段的统计数据可以分为两类：

1. 概要统计数据：如 NDV 字段平均长度 ACL 最大、最小值等

2. 柱状图数据：也叫直方图（histograms）记录 NDV 和它们出现的频率

NDV 也叫做唯一值数，是对表的字段唯一值个数的统计，对于第一类数据，实际上可以通过一次扫描表获取所有字段的统计数据。

但是，对于大型表的分析，为减少资源消耗，需要通过采样分析。由于采样具有随机性，对于一些数据分布不均匀的字段，通过采样数据获取统计数据可能会导致获取到的数据与实际数据产生较大差异。

尤其对于一些海量数据表，通常采样比较低，因而每次分析对象获取到的数据的精度会存在较大的不确定性。这种不确定性可能会对系统的整体性能造成重大影响。     

举个例子

一个字段的里面的数据如下：

[0,1,1,1…(100*1)…1,2,3,4,5,6,7,8,9]

其实际的 NDV 是10，通过采样（假设采样比为10%）获取 NDV 时，由于采样的随机性，可能就会出现以下情况：

[1…(10*1)…,2,6]

得到的 NDV 是3，和实际值存在很大的出入（如果除以采样比的话，NDV 为3/10×100=30）。而如果优化器采样了这样数据进行执行计划代价估算的话，就很有可能获取不到最优的执行计划。

而降低这种不确定性的手段就是提高采样比例。但是，对于大型表来说，提高采样比又会带来更多的资源消耗，尤其是获取 NDV 数值时。

由于获取 NDV 数值需要消除重复值（通过 count (distinct col) 方式获取），Oracle 是通过排序的方法将已经读取的唯一值保持在 PGA 当中，以便消除后续的重复值。因此，当取样比增加时，PGA 的消耗也会线性增加。

对于大型表，PGA 可能不足以容纳全部数据，从而会导致临时磁盘空间的读写，导致重大的性能问题。

在11g中，采用了一种新的算法消除 NDV 计算时，数据量与 PGA 消耗之间的线性关系，从而使得通过完全扫描表获得精确统计数据成为可能。因此，在 11g，自动采样模式下不再进行快速取样，而是直接进行全表扫描获取统计数据。这一新算法称为唯一值数估计（Approximate NDV）。

默认情况下，在进行自动采样时，也就是 AUTO _SAMPLE_SIZE 时，就采样该算法。

这个新特性也可以通过隐含参数 “APPROXIMATE _NDV” 来关闭。

SQL 代码：

HELLODBA.COM>exec dbms_stats.set_param(‘APPROXIMATE_NDV’,’FALSE’);

PL/SQL procedure successfully completed.  

注意：11g 中，对分区表全局统计数据的增量（INCREMENTAL）计算方式，也是利用了该算法。

该算法充分利用了哈希算法的分布均衡特性。其基本算法过程如下：

• 它将每个扫描到的数值通过哈希算法转换为一个二进制数值，并放入一个数据结构中，我们称该数据结构为一个纲要（synopsis）；

• 扫描下一个数值，获取到其哈希二进制数值，将其与纲要中已有哈希值比较，如果已经存在相同值，则丢弃该值，否则就插入纲要中；

• 纲要是有大小限制的，当新插入哈希值时，纲要已经达到大小限制，则按照一定规则分裂该纲要、并丢弃其中一份数据(例如，将首位为0的数值丢弃掉)，此时，纲要级别也相应增加(起始为0，分裂一次加1)；

• 获取到新的哈希数值时，如果其符合被丢弃数据的规则，则不再插入纲要中；

• 再次分裂时，按照递进的规则（如将前2为都为0的数值分裂）丢弃数据，并以此类推，直到扫描完所有数据；

我们称纲要中最终剩下数值数成为集数 (S) ，纲要分裂次数称为级数 (I)

而 NDV 的估算公式是：NDV = S*2^I

在这种算法下，由于每个字段在 PGA 中仅保存一个纲要数据结构，因此，它不会随着读取的数据量的增加而导致 PGA 消耗的增加。

ByJoel Pérez ( Oracle ACE Director )

Do you know how to cancel a single SQL command in Oracle 18c ?

Do you know how to cancel a single SQL command in Oracle 18c ?

Hi Readers

As of Oracle 18c , you can not only abort a database session, but also just a single SQL command. This article shows how it works. Click to read:

Cancel Session in Oracle 18c

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

Read THIS.. Before Patching by April 2019..!!

Warning：Oracle Databases Need to be Patched to a Minimum Patchset/PSU/RU level before April 2019

By Eygle Gai ( Oracle ACE Director )

There are two warning articles which were recently released on Oracle‘s official support site My Oracle Support, have caused widespread concern among users of Oracle Database.

Those two articles’ ID are respectively 2361478.1 and 2335265.1

Different from normal reports or news for oracle users, Oracle point the exact version(11.2.0.3), and specific deadline(before April 2019) for certain Database scenarios（Using DB Links） and operations（Patch）and use the strong word( Mandatory) in the title，make it necessary for oracle users to put it into schedule as the deadline is not so far.

After those two articles were published, many users wondered:

How does Oracle trigger this problem after April 2019, how come the exact time point, could it be a time trigger that Oracle laid into the database?

We did a little research and find out this time constraint does exist, but the real trigger time is: June 23, 2019. (about the time difference, we’ll explain it later)

now, let us analyze it step by step.

As we can see, the document 2361478.1 was created and published on the site on February 15, 2018 

We may remember that on February 16, 2018, the Oracle 18c database was released,

（referring to: Oracle 18c database has been released and new features introduced）

which means this document was released with the new version Oracle 18c, and the new features of 18c can lead to major changes of Oracle Internal mechanism.

Let’s look at some key contents of this article:

What we are announcing:

All supported releases of Oracle Databases need to be patched to a minimum patchset/PSU level before April 2019 to ensure proper functioning of database links. 

Scope of impact: 12.2.0.1 and later versions are not affected, the 11.2.0.4 and 12.1.0.2 patch sets already contain the necessary fixes, and the released patches are available for versions 11.1.0.7 and 11.2.0.3.

Other versions have no patches and need to be upgraded, otherwise there may be problems when connecting other libraries of lower versions and new versions through DB Link.

What changes have caused this effect? The document explain it briefly and effectively as following:

What is the change introduced by the patches listed above?

The patches listed above make the older databases capable of supporting increased SCN soft limit (i.e. support transactions with higher SCN rate) though the increased SCN soft limit only becomes effective later (after April 2019).

Simply put，the algorithm of the SCN needs to be altered, the growth rate to be specific. That way, when data is accessed in multi-DB environment through DB link, the lower and higherversions must use the same algorithm to ensure that the DB Link access is working well.

In those articles, the term “Soft Limit” was described as follows. In the Oracle 11.2.0.2 and before, the threshold of this value 16K,

“At any point in time, the Oracle Database calculates a “not to exceed” limit for the SCN a database can have used, based on the number of seconds elapsed since 1988, multiplied by 16,384. This is known as the ‘Soft Limit’. If the soft limit is likely to be exceeded in the next SCN increment, then Oracle will issue an ORA-0600 error and the process will be cancelled.”

Once the SCN exhausted, problem appeared and the threshold would rise to 32K:

I wrote a article explain how SCN works and may cause problems in the situation of DBlink, you can access that in my blog(www.eygle.com). It works like this: the data query via DB Link will synchronize the SCN of the database. This leads to many Headroom issues that when SCN runs out:

[oracle@jumper oracle]$ sqlplus “/ as sysdba“
SQL*Plus: Release 9.2.0.4.0 – Production on Tue Nov 7 21:07:56 2006
SQL> select dbms_flashback.GET_SYSTEM_CHANGE_NUMBER scn from dual;

      SCN
—————

  5287824

What would happen then?

Some of the clues can already be seen in 18c. This new feature was introduced in official document as following:

Consistency Levels for Multi-Shard Queries

You can specify different consistency levels for queries across multiple shards in a shardeddatabase. For example, you might want some queries to avoid the cost of SCN synchronization across shards, and these shards could be globally distributed. Another use case is when you use standbys for replication and slightly stale data is acceptable for cross-shard queries, as the results could be fetched from the primary and its standbys.  You can use the initialization parameter MULTISHARD_QUERY_DATA_CONSISTENCY to set different consistency levels when executing multi-shard queries across shards.

This feature enables you to avoid the cost of SCN synchronization while executing multi-shard queries across shards and these shards potentially could be distributed globally.

For multi-shard queries, this feature allows slightly stale data from the standby databases.

This feature is currently targeted at the Oracle Sharding database, which means that the cost of SCN synchronization can be avoided in cross-Shard queries.

what does this really mean?

Many customers have been asking questions, which exact BUG should be repaired? Oracle did not answer it in the documentation directly, but it proposes the minimum patch requirements, and different versions of the patch application matrix:

What is the exact minimum patch set we are talking about in this list?

After analyzing, we finally confirmed that the BUG is 14121009, for the minimum patch required to be applied by April 2019 has the exactly same version with the BUG 14121009,Such as 11.2.0.3.9, 11.1.0.7.20, and Windows 11.2.0.3 Patch 28, 11.1.0.7 Patch 57.

So what key function was introduced in this patch and changed the algorithm of Oracle SCN?

From the article we’ve learnt this new feature is SCN compatibility, which has a time limit set in it and requires this patch to be applied.

The command to modify the database SCN algorithm is:

ALTER DATABASE SET SCN COMPATIBILITY.

warnning: do not test it in any of your important environment, it may cause you into big trouble.

The compatibility feature has 4 options that can be changed to three values: 1, 2, 3

SQL> ALTER DATABASE SET SCN COMPATIBILITY 2;

Database altered.

SQL> ALTER DATABASE SET SCN COMPATIBILITY 3;

Database altered.

When the SCN compatibility is modified to a small value, the database needs to be restarted:

The final key question is, what does this all have to do with time?

Our answer is: Oracle sets the time point for each compatibility of the SCN, that means, low-level compatibility will automatically expire in certain time, and all the revised database will beJumped to Compatibility 3 on June 23 2019.

Level 3 allows for a higher SCN growth rate, exceed 32K is possible.

Therefore, if your old database is not upgraded, the database that connects to Level 3 compatibility may immediately exceed the SCN limit, and the data access may be denied.

All this is because Oracle introduced a feature called Auto-RollOver in the kernel, which sets the time for different SCN growth rates and automatically expires. As time goes by, new SCN algorithm will replace the old one yet user known.

You can get the internal information through the DBMS_SCN package. It’s like a time bomb buried in the database

—effective_auto_rollover_ts  – timestamp at which rollover becomes effective

—target_compat         – SCN compatibility value this database

—                  will move to, as a result of auto-rollover

— is_enabled            – TRUE if auto-rollover feature is currently enabled

The reason why Oracle prompts in the warning 2019 April, I think it is to leave the user 84 days of margin.

Based on the above analysis, we also got the answer to following questions which users most concerned:

No, there will be no problem if there are mutual accesses to the low-level databases that have not been patched; however, problems may arise if there is a data access between the unpatched low-level version and the applied high-level version.

Not necessarily, cross-DB Link access is not necessarily a problem, especially if the SCN’s growth rate keeps a low database; however, due to changes in the algorithm, problems are likely to occur, and the probability is high;

Because SCN is Oracle’s core mechanism, the Headroom problem encountered in the past must be eliminated, so the algorithm needs to be adjusted.

It does not matter if the database is maintained at a low version or does not communicate with each other through DB Link; Oracle also provides the function of disabling this feature, but does not guarantee that it will not change afterwards; since versions below 11.2.0.4 are unsupported versions, users are highly recommended to upgrade.

So what happens if something goes wrong? In MOS document 1393360.1, If the lower version of the database SCN cannot be elevated, then ORA-19706: invalid SCN may be encountered.

Rejected the attempt to advance SCN over limit by 9374 hours worth to 0x0c00.00000f66, by distributed transaction remote logon, remote DB: REMDB.XX.ORACLE.COM. 

Client info: DB logon user ME, machine yy, program sqlplus@yy (TNS V1-V3), and OS user uuu

In fact, the last part of this document has revealed changes in the new features of the SCN. In the new version, the SCN’s growth rate can be fully adjusted to be dynamic:

Warning: The SCN intrinsic growth rate has been consistently

higher than system default 16384 per sec. for last 60 mins.

Current SCN intrinsic growth rate is 24416 per sec., zas 7fffff!

The Current SCN value is 3354492471, SCN Compat value is 1

Additional reading related to this topic:

Suggestion and Solution to SCN Compatibility and DB Link Interconnection Issue

The article finishes here!

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

专家视角 | 小荷的 ORACLE DATABASE 18C 新特性快速一瞥

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

Installing Oracle Database 18.0.0.0.0 binaries on Oracle Linux 7

Hi Readers

Install 18c.. Little Hack.. For reading click the image or the link down below.

Installing Oracle Database 18.0.0.0.0 binaries on Oracle Linux 7

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

When will Oracle Database 18c be available “On-prem”?

When will Oracle Database 18c be available “On-prem”?

By Mike Dietrich

When will Oracle Database 18c be available “On-prem”?.. for knowing the answer.. Click the image or the link down below.

When will Oracle Database 18c be available on-prem?

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

Oracle 18c: “Oracle 18c and its impact on DBAs”

By Joel Peréz & Skant Gupta

“DBAs will be fired.. ? It’s the end of DBAs because of the Autonomous Databases..?

Obviously not.. believe it or not.. now the DBAs will have more important role in enterprises.

Later of completing the reading of this article you could read more about new features related to Oracle18c:

Oracle 18c: Oracle 18c.. New Features.. What’s NEWS..

https://blog.enmotech.com/2017/12/17/14-oracle-18c-oracle-18c-new-features-whats-news/

Oracle 18c: New Features for Oracle Data Guard.. What’s NEWS..

https://blog.enmotech.com/2017/12/17/15-oracle-18c-new-features-for-oracle-data-guard-whats-news/

Oracle 18c: RMAN New Features.. What’s NEWS..

https://blog.enmotech.com/2017/12/17/16-oracle-18c-rman-new-features-whats-news/

Oracle 18c: RAC New Features.. What’s NEWS..

https://blog.enmotech.com/2017/12/17/17-oracle-18c-rac-new-features-whats-news/

Oracle 18c: Data Warehousing New Features.. What’s NEWS.

https://blog.enmotech.com/2017/12/17/18-oracle-18c-data-warehousing-new-features-whats-news/

Now, Let’s continue with the article..

I have +17 years as Oracle DBA and I could tell you how this profession have been evolving, having a tendency of:

• More elaborated and advanced features.. that’s the essence of every new release..
• More automated tasks released by release.. the DBAs and Enterprises must realise real advantages to perform early or convenient upgrades before the “Non support of Release” force them to do it..
• and above all.. how to become DBA each day is even more complex than before.. and who will be affected by this.. this is the main point I want to focus in this short article.

Oracle Database 18c the next generation of the industry-leading database.

Oracle introduces the world’s first autonomous database cloud. Oracle Autonomous Database Cloud eliminates complexity, human error, and manual management, helping to ensure higher reliability, security, and more operational efficiency at the lowest cost.

At the previous paragraph I have highlighted the sentences “database cloud” & “Oracle Autonomous Database Cloud“, it means.. when we are talking about Cloud Databases, Oracle Autonomous Database Cloud is just another different kind of Cloud database service, so, in this article we will call it simply as “Cloud Databases”.

Autonomous Databases/Cloud Databases.. is a subject that could be analyzed from different points of views. Most of articles and publications focus in how ideal would be a futuristic database etc..

but Let’s think for a minute about Autonomous Databases..

Who will decide under what kind of service the databases will be.. ?

Who will implant the policies for those autonomous databases ?

Who will have the knowledge to decide or estimate the cost of these services based on the regular activities of those databases ?

Who will decide the complex design of IT Infrastructure when we have more and more options.. ?

The answer is obvious.. a DBA.. not any simple DBA.. a DBA that has evolved with all this new generation of databases on Cloud.

Oracle Autonomous Database as I mentioned before is a kind of different type of a Cloud Database Service. So.. in order to move that database from “On-prem” or create it from zero, a DBA must be needed..

Oracle Autonomous Database is a kind of database with a lot of mundane tasks already automated such as:

• Applying of Patches
• Upgrades
• and Tunes itself..

The more important section of this article is the following

I will use the exact smart words of my colleague Tim Hall ( Oracle ACE Director ) “18c on-prem will have very little impact on DBAs. It is the Autonomous Database suite of services that have the impact”

• “18c on-prem will have very little impact on DBAs”, Yes.. Exactly, Oracle 18c is just another higher version, “Oracle 18c” is not a relational database manager software that will work by default in autonomus mode, in fact, Autonomous Database suite of services has been designed “Up to now” just for Cloud, not for “On-prem” databases.
• “It is the Autonomous Database suite of services that have the impact”, Autonomous databases is a kind of suit of services that will be available for “Oracle Public Cloud”, this means that “On-Prem” databases will not work in autonomous mode “until what we know up to now..”, perhaps later that kind of service could be available for “On-prem databases”

Most of DBAs currently are in fear believing “Autonomous Databases suite of Services” will let them without job.. but the reality is not even near to that.. actually there are several kind of services to lodge a database on Cloud:

• Oracle Database Cloud Service
• Oracle Bare Metal Cloud Database Service
• Oracle Database Exadata Cloud Service
• Oracle Database Exadata Cloud Machine
• Oracle Database Express Cloud Service

“Autonomous Databases suite of Services” will represent just other possible services you could contract

Now, we will see some important points about Autonomous Databases that perhaps most of people does not know..

Oracle self driving database ( Autonomous Database ) will be available starting Oracle18c but there is still a huge period of support for 12cR1/R2. 12cR1 until 4 years more in comparison to this date, we are talking about until 2021 more or less..

12cR2 until April 2025 in extended support. As we know.. Customers normally are not moving so fast to a next release until they need it or until the support period is near to expire. So, Oracle 18c is a release that will be used for customers that really need it or by customers they want to be extreme up to date.

Up to now Oracle self driving database is designed to be run on Exadata, as per we know Exadata is an Engineering system very powerful but not cheap.. so.. most of customers for sure they will not be in Exadata.. it means.. Exadata has a high cost to be the regular hardware for most of regular medium companies around the world

So.. DBA’s no fear.. Oracle self driving database is not Oracle18c.. Oracle self driving database will not be the regular mechanism of your regular databases..

Then, important items to remember later of finishing to read this article:

• Oracle 18c is not Autonomous Database suit of Services
• Autonomous Database Service suit of Services is not Oracle 18c
• Autonomous Database suit of Services is a kind of services available up to now just for Oracle Public Cloud
• Autonomous Database suit of Services will run just in Exadata ( “According to the information we have up to now, later perhaps could change..”)
• Oracle 18c is just one release more

So.. with those lines you have got the more important section of this article.

The conclusion is that “Oracle 18c” will have little impact for regular “On-prem” databases and databases services related to “self driving”

Now, Let’s extend this conversation..

But Let’s wait a minute.. Let’s analyze every one of those.. how it can be done today with the regular “Oracle Database Cloud Service (DBCS)” and how we think Oracle will do it.. We talk about “How Oracle will do it.. because the debut of Autonomous Datawarehouse Database Cloud will be in December 2017.

Applying of Patches: nowadays, if you want to apply a Patch using DBCS is just to go to the console, see on the screen if there is any available patch for that database and make some clicks to apply it.. So simple..

So.. I think is not “so difficult” for Oracle Corp, replace our clicks for an automated process..

There are some patches that require the database must be stopped because they change binaries.. etc.. well.. most probable Oracle had already a mechanism in order to apply patches having the database running and they have decided to release it now.. if we imagine how work the database inside running sequentially sentences.. etc.. every sentence.. operations.. etc all this can be coordinated so that patches affect in some way “post” sentences.. etc.. in a general way what I’m trying to say is.. the fact of applying patches by itself is not the big thing taking into account the level of development of the Oracle product during years.. So.. the applying patch by itself is just a step forward related to levels of automation.

Upgrades: Up to now when you are working with DBCS the only way to upgrade a database already working in the cloud is creating another service which will have another compute node and we apply a regular procedure to upgrade that database. However, we have to remember that Oracle has been working very hard in establish very advance mechanism to manage PDB. Nowadays we can clone PDB in hot, we can move PDBs from one container to another container in hot.. basically is very alike to the mechanism implanted to move a datafile online.. so.. this technology is extreme mature by the Oracle Software in these times.. So.. Upgrade a database must be surely a procedure a alike to what is done with PDB, the CDB in its root definition has the binaries of the corresponding version and we move just the data. I’m “sure”.. that’s the mechanism the Oracle software will use to upgrade databases in hot. So.. if we realise all I have commented.. all this is just a technology that we are using with the current release.. difference in autonomous databases is that they are applying this procedure with complete databases under this kind of new service.

Note : later of writing this article my colleague Tim Hall ( Oracle ACE Director ) had helped me to clarify that element, these are the exact words of Tim

“Oracle have explained how the upgrades and patches will work. These systems are based on 18c running on Exadata. Since 18c allows rolling upgrades and patches for everything, including OJVM, they are able to do online patches for these services“

Thanks Tim!!

Tunes itself: is even more easy to explain.. when you tune queries using adaptive technics.. etc.. all this can happen with the databases running.. rebuild indexes online.. etc.. must of tune operations nowadays can be done online.. it’s not so difficult to have an AI ( Artificial Intelligence ) engine collecting data and taking some decisions based on internal tests.. statistics.. etc.. so.. this new level of automation/autonomous is just what we have but being done automatically.

Let’s talk with what frequency we do these tasks:

Applying of Patches: time to time.. It’s not so frequent.. so.. there are not too much changes to appreciate in the time we employ in this task

Upgrades: even less.. it’s very seldom when we apply upgrades to the databases.. so.. there are not too much changes to appreciate in the time we employ in this task

Tunes itself: tuning.. yes.. many companies.. consultants.. etc.. employ a lot of time in constant tuning to databases for many reasons.. it’s very common that some objects.. some queries.. some code.. etc are added, removed.. changed in the database and of course this generate variations in the performance. This point could impact relatively highly the cost of many enterprises, because tuning a database constantly imply constant high costs. Of course.. we have to see how good the engine can be doing this. We have to remember that currently we have available “Tuning advisors” and they are not perfect.. sometimes we apply some recommendations and the performance of some executions.. etc.. become worst.. so.. the factor of “Tuning itself”.. really.. thinking very honest.. we have to see how that will work. If the results are very good and convenient.. definitely this factor will reduce a lot of cost to enterprises and of course will affect in some way DBAs specialized or in charge of tuning.

In December 2017 will be release the autonomous database service for Data warehouse, later on 2018 for OLTP and so on..

The tuning itself for Data Warehouse databases is easier than for OLTP Database according to my point of view. The typical and common operations.. ( Load.. queries.. etc ) are more common between them than for an OLTP database.

When you analize the conditions that will have autonomous databases for DW, you start to discover how it will work internally..

These are just some of them..

Automated Database Configuration for Autonomous DB for DW

• init.ora parameters

– Parameters optimized for DW workloads

– Memory, parallelism, sessions configured based on number of CPUs – Users can modify a limited set of parameters, e.g. NLS setttings

• Tablespace management

– Pre-defined data and temporary tablespaces – Users cannot create/modify tablespaces

• Compression

– All tables compressed using Hybrid Columnar Compression – Users cannot change compression method or disable compression

• Optimizer stats gathering

– Stats gathered automatically during direct load operations – Users can gather stats manually if they want

• Optimizer hints

– Hints ignored by default – Users can enable hints explicitly

• Result cache configuration

– Result cache enabled by default for all queries

and more.. I’ll talk more in detail about all this in an article dedicated to Autonomous DBs for DW.

Let’s come back a bit to the topic we were talking about automation and how enterprises can deal with that..

So.. one important thing to think.. You guess Enterprises with extreme important databases will allow to run all these tuning.. etc.. by itself without someone that can be monitoring what the database is doing.. ?

We are going to be honest.. Enterprises with critical databases will not allow to give the 100% of confidence to an engine software to tune itself on demand without control or supervision of a human. Of course, there are some databases.. under some levels of importance.. circumstances that fit that model.. to be tuned 100% without supervision but that not the regular cases.

That self tuning will have sections.. factor.. policies.. etc.. and DBAs will choose what elements could be tune by itself.. and which of them will keep under control of DBAs. At the end.. always DBAs will be needed.. Now DBAs will have more facilities to do their jobs more easy.. but that fact of thinking to replace totally the humans is something difficult to happen in spite of the engine can take correct decisions.

Let’s describe a simple example.. Oracle Data Guard has the option to FAILOVER automatically under some circumstances, but for some possible humans errors could happen a database can failover when the humans did not want it.. so.. most of enterprises they fear to use FSF ( Fast Start Failover ), It’s a mechanism that works perfect technically but to give the total control to the software to apply something critical to the data is something most of enterprises are not allow to implant.

In a general way I think autonomous databases will reduce tons of working hours for DBAs but will not represent in a practical and real way the elimination of Human presence.

So, autonomous databases promises the following:

Less time on Administration

– Less time on infrastructure

– Less time on patching, upgrades

– Less time on ensuring availability

– Less time on tuning

More time on Innovation

– More time on database design

– More time on data analytics

– More time on data polices

– and very important.. More time on securing data

So.. with databases on Cloud, DBAs must strength their skills in Security

Now Let’s jump to another point of analysis..

Future of DBAs related to Oracle Database Cloud

17 years ago.. it was so simple to design a database architecture. You had to decide to lodge your database in a:

• Server..
• Or in a Mainframe
• Or even in a regular desktop machine in some cases..

Now, when DBAs will decide where to lodge databases must think in many options.. such as:

• – Servers..
• – Virtual Machines
• – Engineering Systems such as “Exadata”
• – and more..

They have to decide if the architecture will be implanted:

• – “On-Prem” as the regular option
• – Cloud in our own data center ( Private Cloud )
• – Hybrid Cloud
• – Public Cloud, now the public Cloud has more options with autonomous databases in Oracle18c.. etc

and more and more..

Before was so simple to design a database architecture.. now not.. Now we have a lot of options.. each one with pros and cons. Basically is a sea of options..

So.. the question is.. Who will be in charge of designing all this.. ?

The General Managers ? obviously not.. this will be designed by Database Architects.. ( DBAs )

Now DBAs will be asked more to understand the business rather than just the mechanics of keeping the database healthy and running

Before the cost of Servers.. services.. etc.. was not the main thing with what DBAs had to deal.. they were focused just in keeping the database running and implanting them. Now is different.. , now creating a database in Cloud, for example.. implies a decision of what kind of service to use and in what mode.. “Metered.. Non-Metered..” etc.. those factors impact directly the economy of the enterprise and the mode of operating these databases, so.. now the DBAs are more related into the business.

Some years ago from the first minute Oracle Corp. announced the release of “Oracle Cloud”, another level of expertise for DBAs was born, turning this business more complex..

DBAs will not be fired.. now the roles of DBAs are even more important.. the role of DBAs is simply shifting to be more of a role of architect..

Who must worry because of all these changes.. ?

Those kind of operational DBAs who are or were in charge just of doing simple tasks.. such as:

– Checking Backups..

– Checking storage..

– Making some reports..

– Installing Patchs..

– Installing softwares..

– Creating constantly new environments for developers..

All those easy and simple tasks.. have been removing with the addition of automation in Oracle Releases..

For instance, now at the time of creating an Oracle Database Cloud Service, there are many elements created automatically including:

– The creation of compute node ( Host )

– Installation of Software

– and more..

Here you can see how simple can be create a disaster recovery configuration on Cloud using Data Guard:

#1 Oracle Cloud (DBaaS): Oracle Data Guard in Database Cloud Service ( DBCS )

So.. with just this simple example.. you can realise that at the time of working with Oracle Database Cloud Service you do not have to install softwares anymore..

If you want to create a RAC configuration in a using Oracle Database Cloud Service is just some simple clicks and you could have complex RAC-DG configurations.

The era of regular and boring tasks is getting away.. so.. if you are a DBA in charge of those kind of simple tasks.. yes.. worry about your future..

Contrary of this, if you are a DBA in charge of implanting MAA architectures.. Cloud Databases, Exadata.. etc.. happy for you.. the importance of your role now will be bigger..

So.. now we come back to the central point of this article..

you can imagine what will be the vision of a person that is starting as DBA with all these numerous options in the market.. A person that is barely learning SQL.. and “Create table..” etc.. when the market is talking about autonomous databases.. It’s a comparison like between a kid bike and one 1000cc Motorbike.. something like that..

My though about all this is:

#1.- DBAs with kind of regular maintenance tasks.. could be removing from their role or job if they do not evolve to be focused in all this new generation related to Cloud

#2.- DBAs that have got the privilege to work with Oracle Databases during the golden era of “On-prem” databases, now they are in the right time to grow in parallel with something that is defining the “before” and “after” of IT. Now the DBAs will have the opportunity to move into a more strategic role in their organisations and based on that the income “salary.. commissions.. etc” will be higher.. now you will be involved in important decisions for the company

#3.- Sorry for new DBAs entering in this database world.. the journey you have to run is even harder than before to get the top level in this area because day by day are generated more and more options

Conclusion

1.- If you are a DBA kind #1 according to the previous description, perhaps you have several options.. evolve to #2, or if you decide to stay in the same role, your payment could be less over time or your role could be slowly disappear.

2.- If you are a DBA kind #2, keep on the track.. and your role will be more and more important in this field, by consequence your payment will have high probabilities to be increased. One more thing.. most of DBAs will not reach to be Cloud architects because this require time of study.. researching.. testing.. etc.. so.. feel proud if you reach it and take advantage of that inside your current or future organizations

3.- If you are a DBA kind #3, do not give up.. do not see the journey too long as It really is, just keep learning and you will get the level to be a good competitor in the market.

Now, perhaps you have the question.. How I can start to get ready to administer databases on Cloud ?

I could tell you, go to https://www.oracle.com/cloud/index.html and start there..

The page is the starting point of that monster called “Oracle Cloud.. ( PaaS, IaaS, SaaS..) etc etc”, you could be lost easily.

If you are DBA and you are interested in managing databases on Cloud, my main recommendation is to follow the path to become OCP Cloud.

The OCP Cloud has the base and initial path of knowledge that every DBA must domain to work with databases on Cloud.

This article finish here. If you have liked, go down below and share it in your prefer social medias: LinkedIn, Facebook.. etc. Thanks!!

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Author Bios:

Joel Pérez is an Expert DBA ( Oracle ACE Director, Maximum Availability OCM, OCM Cloud Admin. & OCM12c/11g ) with over 17 years of Real World Experience in Oracle Technology, specialised in design and implement solutions of: High Availability, Disaster Recovery, Upgrades, Replication, Cloud and all area related to Oracle Databases. International consultant with duties, conferences & activities in more than 50 countries and countless clients around the world. Habitual and one of leading writers of Technical Oracle articles for: OTN Spanish, Portuguese, English and more. Regular Speaker in worldwide Oracle events like: OTN LAD (Latin America), OTN MENA (Middle East & Africa), OTN APAC ( Asian Pacific), DTCC China, Oracle Code.. . Joel has always been known for being a pioneer in Oracle technology since the early days of his career being the first Latin American awarded as “OTN Expert” at year 2003 by Oracle Corp., one of the first “Oracle ACE” globally in the Oracle ACE Program at year 2004. He was honoured as one of the first “OCM Database Cloud Administrator” & Maximum Availability OCM in the world. Currently Joel works as Senior Cloud Database Architect in “Yunhe Enmo (Beijing) Technology Co.,Ltd”., company located in Beijing, China En.enmotech.com

Skant Gupta is an Oracle Certified Cloud Professional in Oracle Database 12c, an Oracle Certified Expert in Oracle Real Application Clusters (Oracle RAC) in Oracle Database 11g and 12c, and an Oracle Exadata Certified and an Oracle Certified Professional in Oracle Database 10g, 11g, and 12c. He works at Vodafone Technology in the UK and formerly worked as a senior DBA at Etisalat in Dubai. He has six years of experience with various Oracle technologies, focusing mainly on Cloud, database, and high availability solutions, Oracle WebLogic Suite, Oracle Exadata and Oracle GoldenGate. He has presented at several Oracle user groups worldwide, most recently in the US, the United Arab Emirates, and the India. Skant website link: oracle-help.co

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ByJoel Pérez ( Oracle ACE Director )

Oracle Database 18c Now Available on Oracle Database Appliance..!!

Oracle Database 18c Now Available on Oracle Database Appliance..!!

Hi Readers

We  are happy to announce the availability of Oracle Database 18c on Oracle Database Appliance.   This Database Appliance release marks a new and exciting time, giving you the opportunity to start testing and using the new Oracle Database 18c functionality and improvements with your applications.

For Reading all the details about click the image or the link down below

For Reading Click here: https://blogs.oracle.com/oda/oracle-database-18c-oda

We hope the content could be useful for your Oracle DBA Tasks!

ByJoel Pérez ( Oracle ACE Director )

For Oracle DBAs.. CrashSimulator..!!

For Oracle DBAs.. CrashSimulator..!!

Hi Readers

CrashSimulator by Francisco Alvarez is able to provide you with almost 50 different scenarios for CDB and Non-CDB Databases and the best part.. It’s free.. read more about it clicking the image or at the link down below.

For Reading click here: http://oraclenz.org/?page_id=4301

We hope the content could be useful for your Oracle DBA Tasks!