Re: Additional Chapter for Tutorial - (review first half of 0003)

On 2020-04-29 16:13, Jürgen Purtz wrote:
> On 20.04.20 10:30, Jürgen Purtz wrote:
>> On 17.04.20 20:40, Erik Rijkers wrote:
>>> Very good stuff, and useful. I think.
>>>
>>> I mean that but nevertheless here is a lot of comment :)
>>>
>>> (I didn't fully compile as docs, just read the 'text' from the patch
>>> file)
>>
>> Thanks. Added nearly all of the suggestions.
>>
>>
> What is new? Added two sub-chapters 'mvcc' and 'vacuum' plus graphics.
> Made some modifications in previous sub-chapters and in existing
> titles. Added some glossary entries.

> [0003-architecture.patch]

Hi Jürgen,

Here are again some suggested changes, up to line 600 (of the patch -
that is around start of the new NVCC paragraph)

I may have repeated some thing you have already rejected (it was too
much work to go back and check). I am not a native speaker of english.

One general remark: in my humble opinion, you write too many capitalized
words. It's not really a problem but overall it's becomes bit too much.
But I have not marked these. perhaps some future iteration.

I'll probably read through the latter part of the patch later (probably
tomorrow).

Thanks,

Erik Rijkers

they merely send requests to the server side and receives
they merely send requests to the server side and receive

is a group of tightly coupled other server side processes plus a
is a group of tightly coupled other server-side processes plus a

Client requests (SELECT, UPDATE, ...) usually leads to the
Client requests (SELECT, UPDATE, ...) usually lead to the

Because files are much larger than memory, it's likely that
Because files are often larger than memory, it's likely that

RAM is performed in units of complete pages, retaining their size and
layout.
RAM is performed in units of complete pages.

Reading file pages is notedly slower than reading
Reading file pages is slower than reading

of the <firstterm>Backend processes</firstterm> has done the job those
pages are available for all other
of the <firstterm>Backend processes</firstterm> has read pages into
memory those pages are available for all other

they must be transferred back to disk. This is a two-step process.
they must be written back to disk. This is a two-step process.

Because of the sequential nature of this writing, it is much
Because of this writing is sequential, it is much

in an independent process. Nevertheless all
in an independent process. Nevertheless, all

huge I/O activities can block other processes significantly,
I/O activities can block other processes,

it starts periodically and acts only for a short period.
it starts periodically and is active only for a short period.

duty. As its name suggests, he has to create
duty. As its name suggests, it has to create

In consequence, after a <firstterm>Checkpoint</firstterm>
After a <firstterm>Checkpoint</firstterm>,

In correlation with data changes,
As a result of data changes,

text lines about serious and non-serious events which can happen
text lines about serious and less serious events which can happen

database contains many <glossterm
linkend="glossary-schema">schema</glossterm>,
database contains many <glossterm
linkend="glossary-schema">schemas</glossterm>,

belongs to a certain <firstterm>schema</firstterm>, they cannot
belongs to a single <firstterm>schema</firstterm>, they cannot

A <firstterm>Cluster</firstterm> is the outer frame for a
A <firstterm>Cluster</firstterm> is the outer container for a

<literal>postgres</literal> as a copy of
<literal>postgres</literal> is generated as a copy of

role of <literal>template0</literal> as the origin
role of <literal>template0</literal> as the pristine origin

are different objects and absolutely independent from each
are different objects and independent from each

complete <firstterm>cluster</firstterm>, independent from
<firstterm>cluster</firstterm>, independent from

anywhere in the file system. In many cases, the environment
somewhere in the file system. In many cases, the environment

some files, all of which are necessary to store long lasting
some files, all of which are necessary to store long-lasting

<firstterm>tablespaces</firstterm> itself.
<firstterm>tablespaces</firstterm> themselves.

<firstterm>Postgres</firstterm> (respectively
<firstterm>Postmaster</firstterm>) process.
<firstterm>Postgres</firstterm> process (also known as
<firstterm>Postmaster</firstterm>).

<title>MVCC</title>
<title>MVCC - Multiversion Concurrency Control</title>

The dabase must take a sensible decision to prevent the application
The database must take a sensible decision to prevent the application

# this sentence I just don't understand - can you please elucidate?
The database must take a sensible decision to prevent the application
from promising delivery of the single article to both clients.