<div dir="auto"><div><br><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il mar 27 ago 2019, 17:07 Alessandro Luccaroni - Diennea <<a href="mailto:alessandro.luccaroni@diennea.com">alessandro.luccaroni@diennea.com</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="IT" link="blue" vlink="purple">
<div class="m_-2708892515594625988WordSection1">
<p class="MsoNormal"><span>Merged your last notes with my previous updated list:<u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><b>Checkpoints =</b> "Consistent" "Blocking" (HerdDB supports periodic checkpoints, every 15 minutes by default. At checkpoints, active page ids are written to disk with their current log sequence numbers. At the same time all dirty pages
are discarded and their records used to build new pages, among other new or updated records. Checkpoints can be tuned to be either as fast as possible or as clean as possible. Fast checkpoints block write operations for less time, whereas clean checkpoints
optimize memory usage (fewer dirty pages left in memory) and speeds up searches (fewer dirty pages left on disk).) (<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>
<a href="https://github.com/diennea/herddb/wiki/Checkpoints-configuration" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Checkpoints-configuration</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Concurrency Control</b> = " Deterministic Concurrency Control" (Before accessing records, clients acquire read or write locks. Every transaction that modifies a record holds the new data in a local buffer copy, and this new version of
the record is not visible to other transactions until that one is committed (Pessimistic Row Level Locking).)<u></u><u></u></p>
<p class="MsoNormal"><b>Foreign Keys =</b> "Not Supported" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Data Model =</b> "Relational" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Indexes =</b> "B-Link" "BRIN" <span>
(Block Range Index implementation is not strictly speaking the official BRIN implementation you can find in literature, so we can talk about “BRIN-like” indexes)<u></u><u></u></span></p>
<p class="MsoNormal"><b>Isolation Levels =</b> "Read Committed" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Joins =</b> "Nested Loop Join" "Sort-Merge Join" "Hash Join" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Logging =</b> "Physical Logging" (Build upon Apache BookKeeper)<u></u><u></u></p>
<p class="MsoNormal"><b>Query Compilation =</b> "<span lang="EN-US">Not Supported</span>"<u></u><u></u></p>
<p class="MsoNormal"><b>Query Execution =</b> "Tuple-at-a-Time Mode"<u></u><u></u></p>
<p class="MsoNormal"><b>Query Interface =</b> "SQL" "Command-line/Shell" "Custom API" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Storage Architecture =</b> "Disk-oriented" (<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Storage Model =</b> "N-ary Storage Model (Row/Record)" (HerdDB’s internal architecture stores a table as a set of key-value entries. This is implemented in Java by a very large map of binary data. Each row is translated from column-oriented
to key-value format by tearing apart the “primary key” part (one or multiple columns) from the “value” part (other columns).) (<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Storage Organization =</b> "Log-structured" (Built upon Apache BookKeeper.</p></div></div></blockquote></div></div><div dir="auto">This is partially true, I won't say that</div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="IT" link="blue" vlink="purple"><div class="m_-2708892515594625988WordSection1"><p class="MsoNormal"> At any given time, some part of data is stored in a memory buffer and some other on disk. No data will be lost on JVM crashes, because transaction logs are the
source-of-truth and the whole database can be recovered from them plus a checkpoint. When a row is stored on disk it is assigned to a "data page"; on its first mutation, it is detached from its data page and that page is marked as “dirty”. At checkpoints,
all dirty pages are dismissed and their records used to build new pages, among other new or updated records. Records modified/inserted/deleted in the scope of a transaction are never written to disk and they are not present in the main buffer until that transaction
is committed, so that there always is a consistent and committed data snapshot. Every transaction uses its own local buffer to store temporary data.) (<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>)
(<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Stored Procedures =</b> "Not Supported" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>System Architecture =</b> "Shared-Nothing" (Built upon Apache Zookeeper and Apache BookKeeper.) (<a href="https://github.com/diennea/herddb/wiki/Replication" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Replication</a>)<u></u><u></u></p>
<p class="MsoNormal"><b>Views =</b> "Not Supported" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><span>What do you think?<br>
<br>
Ale<u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
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<p class="MsoNormal"><b>Da:</b> <a href="mailto:herddb-dev-bounces@lists.herddb.org" target="_blank" rel="noreferrer">herddb-dev-bounces@lists.herddb.org</a> <<a href="mailto:herddb-dev-bounces@lists.herddb.org" target="_blank" rel="noreferrer">herddb-dev-bounces@lists.herddb.org</a>>
<b>Per conto di </b>Enrico Olivelli<br>
<b>Inviato:</b> martedì 27 agosto 2019 17:00<br>
<b>A:</b> Herddb developers <<a href="mailto:herddb-dev@lists.herddb.org" target="_blank" rel="noreferrer">herddb-dev@lists.herddb.org</a>><br>
<b>Oggetto:</b> Re: [Herddb-dev] Herddb entry on <a href="http://dbdb.io" target="_blank" rel="noreferrer">dbdb.io</a><u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Alessandro<u></u><u></u></p>
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<p class="MsoNormal">Overall looks good<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Last answers inline below<u></u><u></u></p>
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<div>
<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Enrico<u></u><u></u></p>
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<p class="MsoNormal">Il gio 27 giu 2019, 16:09 Alessandro Luccaroni - Diennea <<a href="mailto:alessandro.luccaroni@diennea.com" target="_blank" rel="noreferrer">alessandro.luccaroni@diennea.com</a>> ha scritto:<u></u><u></u></p>
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<p class="MsoNormal"><span lang="EN-US">Hi all,</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">I was thinking about sending an email to Carnagie Mellon Database Group about the entry of Herddb on
<a href="https://dbdb.io/db/herddb" target="_blank" rel="noreferrer">https://dbdb.io/db/herddb</a></span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">I’ve grouped up a bunch of information about Herd, can you check if everything seems correct?</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Checkpoints = "Consistent" (<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>
<a href="https://github.com/diennea/herddb/wiki/Checkpoints-configuration" target="_blank" rel="noreferrer">
https://github.com/diennea/herddb/wiki/Checkpoints-configuration</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Foreign Keys = "Not Supported" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)</span><u></u><u></u></p>
<p class="MsoNormal">Data Model = "Relational" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)<u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Indexes = "B-Link" "BRIN" (<a href="https://github.com/diennea/herddb/blob/master/herddb-utils/src/main/java/herddb/index/blink/BLink.java" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/blob/master/herddb-utils/src/main/java/herddb/index/blink/BLink.java</a>
<a href="https://github.com/diennea/herddb/tree/master/herddb-core/src/main/java/herddb/index/brin" target="_blank" rel="noreferrer">
https://github.com/diennea/herddb/tree/master/herddb-core/src/main/java/herddb/index/brin</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Isolation Levels = "Read Committed" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Joins = "Nested Loop join" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Query Interface = "SQL" "Command-line/Shell" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Storage Architecture = "Hybrid"
</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Storage Model = "Key/Value" "N-ary Storage Model (Row/Record)" (<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Storage Organization = "Log-structured" "Heaps" (<a href="https://github.com/diennea/herddb/wiki/Data-storage" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Data-storage</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Stored Procedures = "Not Supported" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">System Architecture = "Shared-Nothing" (<a href="https://github.com/diennea/herddb/wiki/Replication" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/Replication</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">Views = "Not Supported" (<a href="https://github.com/diennea/herddb/wiki/SQL-Support" target="_blank" rel="noreferrer">https://github.com/diennea/herddb/wiki/SQL-Support</a>)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">I’m still in doubt about some other definition, see below with some “option” using the
<a href="http://dbdb.io" target="_blank" rel="noreferrer">dbdb.io</a> “nomenclature”:</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">“Concurrency Control”</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">1)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Deterministic Concurrency Control</span><u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">This one is the best<u></u><u></u></p>
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<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">2)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Multi-version Concurrency Control (MVCC)</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">3)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Optimistic Concurrency Control (OCC)</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">4)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Timestamp Ordering</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">5)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Two-Phase Locking (Deadlock Detection)</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">6)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Two-Phase Locking (Deadlock Prevention)</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">“Query Compilation”</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">1)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Code Generation</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">2)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">JIT Compilation</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">3)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Not Supported</span><u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<div>
<p class="MsoNormal"><u></u> <u></u></p>
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<div>
<p class="MsoNormal">This is better<u></u><u></u></p>
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<blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
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<div>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">4)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Stored Procedure Compilation</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">“Query Execution”</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">1)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Materialized Model</span><u></u><u></u></p>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">2)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Tuple-at-a-Time Model</span><u></u><u></u></p>
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<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">This one<u></u><u></u></p>
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<div>
<blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
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<div>
<p class="m_-2708892515594625988m98043319007277627msolistparagraph"><span lang="EN-US">3)</span><span lang="EN-US" style="font-size:7.0pt;font-family:"Times New Roman",serif">
</span><span lang="EN-US">Vectorized Model</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US">But we could also use some terminology that is not currently cover (for example currently there are no DBMS mapped with either BRIN or B-Link indexes, but we
support them).</span><u></u><u></u></p>
<p class="MsoNormal"><span lang="EN-US"> </span><u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:13.0pt;font-family:"Arial",sans-serif">Alessandro Luccaroni</span></b>
<br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">Platform Manager @ Diennea - MagNews<br>
</span><span style="font-size:8.5pt;font-family:"Arial",sans-serif">Tel.: (+39) 0546 066100 Int. 924 - Mob.: (+39) 393 7273519</span><br>
<span style="font-size:8.5pt;font-family:"Arial",sans-serif">Viale G.Marconi 30/14 - 48018 Faenza (RA) - Italy</span><u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
<div class="MsoNormal" align="center" style="text-align:center">
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