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    <p><code>PostgreSQL</code> does have this concept.</p> <p>See <a href="http://www.commandprompt.com/ppbook/x4636" rel="nofollow noreferrer"><strong>here</strong></a> for a brief list of pseudocolumns in <code>PostgreSQL</code>, out of which <code>ctid</code> is of interest to you:</p> <blockquote> <p><code>ctid (tuple identifier)</code></p> <p>The identifier which describes the physical location of the tuple within the database. A pair of numbers are represented by the ctid: the block number, and tuple index within that block.</p> </blockquote> <p>That is direct analog of <code>Oracle</code>'s <code>rowid</code>.</p> <p>As for <code>MySQL</code>, physical location of a row is not available for the front end.</p> <p>In <code>MyISAM</code>, <code>rowid</code> is just a file offset from the beginning, and that's what is stored in the index leaves.</p> <p>In <code>InnoDB</code>, tables are <code>index organized</code> by design, that means they always have some kind of a primary key, and the indexes over an <code>InnoDB</code> table use that <code>PRIMARY KEY</code> as a row pointer.</p> <p>This is also true for <code>Oracle</code>'s <code>index organized</code> tables, for which a <code>rowid</code> is not a physical pointer to a block in a datafile, but rather a such called <code>logical ROWID</code>, or <code>UROWID</code></p> <p>If you select a <code>ROWID</code> from an <code>INDEX ORGANIZED</code> table in <code>Oracle</code>, you will see that it has a different format (something like <code>*BAEBwPICwQL+</code>). This is in fact an encoded <code>PRIMARY KEY</code> value.</p> <p>Note that if you have not defined any column as a <code>PRIMARY KEY</code>, <code>MySQL</code> will create a hidden surrogate <code>PRIMARY KEY</code> over which you will never have any control.</p> <p>That's why you should always create some kind of a <code>PRIMARY KEY</code> in an <code>InnoDB</code> table: it's free, and you get control over the column.</p>
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    1. POIs there an open-source SQL database that has the concept of Oracle's "rowid" pseudo-column?
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    1. USQuassnoi
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    1. POIs there an open-source SQL database that has the concept of Oracle's "rowid" pseudo-column?
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    1. COIt does? I Googled for the answer, and found a forum post saying that PostgresQL does not have that concept.
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      1. USJames Mishra
    2. COJust try it if you don't believe me :)
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      1. USQuassnoi
    3. COBy the way: by ROWID in Oracle you mean ROWID (physical pointer to a data block containing a record) or ROWNUM (incremental row number in a dataset returned from a SELECT query)? These are different things.
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Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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