diff options
author | Tom Lane | 2004-12-17 04:50:32 +0000 |
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committer | Tom Lane | 2004-12-17 04:50:32 +0000 |
commit | 92c001bbaf86ac171fb361e81aa962ae873b52c2 (patch) | |
tree | 03b4f253c7e1dfd05e46d1969c3915f86fca7ddd | |
parent | 1ef38f26919bec1b9d4b4a9273dec4d992a88040 (diff) |
Minor copy-editing in tutorial.
-rw-r--r-- | doc/src/sgml/advanced.sgml | 4 | ||||
-rw-r--r-- | doc/src/sgml/query.sgml | 26 | ||||
-rw-r--r-- | doc/src/sgml/start.sgml | 4 |
3 files changed, 17 insertions, 17 deletions
diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 64ff4616e2d..82d9e229b3f 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/advanced.sgml,v 1.46 2004/11/15 06:32:13 neilc Exp $ +$PostgreSQL: pgsql/doc/src/sgml/advanced.sgml,v 1.47 2004/12/17 04:50:32 tgl Exp $ --> <chapter id="tutorial-advanced"> @@ -196,7 +196,7 @@ UPDATE branches SET balance = balance + 100.00 and won't be lost even if a crash ensues shortly thereafter. For example, if we are recording a cash withdrawal by Bob, we do not want any chance that the debit to his account will - disappear in a crash just as he walks out the bank door. + disappear in a crash just after he walks out the bank door. A transactional database guarantees that all the updates made by a transaction are logged in permanent storage (i.e., on disk) before the transaction is reported complete. diff --git a/doc/src/sgml/query.sgml b/doc/src/sgml/query.sgml index 8240281b3d5..33294afd3c5 100644 --- a/doc/src/sgml/query.sgml +++ b/doc/src/sgml/query.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/query.sgml,v 1.40 2004/11/15 06:32:14 neilc Exp $ +$PostgreSQL: pgsql/doc/src/sgml/query.sgml,v 1.41 2004/12/17 04:50:32 tgl Exp $ --> <chapter id="tutorial-sql"> @@ -154,7 +154,7 @@ CREATE TABLE weather ( </para> <para> - <productname>PostgreSQL</productname> supports the usual + <productname>PostgreSQL</productname> supports the standard <acronym>SQL</acronym> types <type>int</type>, <type>smallint</type>, <type>real</type>, <type>double precision</type>, <type>char(<replaceable>N</>)</type>, @@ -297,8 +297,8 @@ SELECT * FROM weather; <footnote> <para> While <literal>SELECT *</literal> is useful for off-the-cuff - queries, it is considered bad style in production code for - maintenance reasons: adding a column to the table changes the results. + queries, it is widely considered bad style in production code, + since adding a column to the table would change the results. </para> </footnote> The output should be: @@ -400,9 +400,9 @@ SELECT DISTINCT city the cities table, and select the pairs of rows where these values match. <note> <para> - This is only a conceptual model. The actual join may - be performed in a more efficient manner, but this is invisible - to the user. + This is only a conceptual model. The join is usually performed + in a more efficient manner than actually comparing each possible + pair of rows, but this is invisible to the user. </para> </note> This would be accomplished by the following query: @@ -727,15 +727,15 @@ SELECT city, max(temp_lo) aggregates are computed. Thus, the <literal>WHERE</literal> clause must not contain aggregate functions; it makes no sense to try to use an aggregate to determine which rows - will be inputs to the aggregates. On the other hand, + will be inputs to the aggregates. On the other hand, the <literal>HAVING</literal> clause always contains aggregate functions. (Strictly speaking, you are allowed to write a <literal>HAVING</literal> - clause that doesn't use aggregates, but it's wasteful: The same condition + clause that doesn't use aggregates, but it's wasteful. The same condition could be used more efficiently at the <literal>WHERE</literal> stage.) </para> <para> - Observe that we can apply the city name restriction in + In the previous example, we can apply the city name restriction in <literal>WHERE</literal>, since it needs no aggregate. This is more efficient than adding the restriction to <literal>HAVING</literal>, because we avoid doing the grouping and aggregate calculations @@ -788,10 +788,10 @@ SELECT * FROM weather; </indexterm> <para> + Rows can be removed from a table using the <command>DELETE</command> + command. Suppose you are no longer interested in the weather of Hayward. - Then you can do the following to delete those rows from the table. - Deletions are performed using the <command>DELETE</command> - command: + Then you can do the following to delete those rows from the table: <programlisting> DELETE FROM weather WHERE city = 'Hayward'; </programlisting> diff --git a/doc/src/sgml/start.sgml b/doc/src/sgml/start.sgml index fc53a20a144..c40f76c8ce3 100644 --- a/doc/src/sgml/start.sgml +++ b/doc/src/sgml/start.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/start.sgml,v 1.36 2004/06/29 19:57:40 petere Exp $ +$PostgreSQL: pgsql/doc/src/sgml/start.sgml,v 1.37 2004/12/17 04:50:32 tgl Exp $ --> <chapter id="tutorial-start"> @@ -218,7 +218,7 @@ createdb: database creation failed: ERROR: permission denied to create database operating system account. As it happens, there will always be a <productname>PostgreSQL</productname> user account that has the same name as the operating system user that started the server, - and it also happens that the user always has permission to + and it also happens that that user always has permission to create databases. Instead of logging in as that user you can also specify the <option>-U</option> option everywhere to select a <productname>PostgreSQL</productname> user name to connect as. |