table: docs: fix typos and grammar.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20190404055138.GA24864@telsasoft.com

doc/src/sgml/catalogs.sgml

@@ -587,7 +587,7 @@
    The catalog <structname>pg_am</structname> stores information about
    relation access methods.  There is one row for each access method supported
    by the system.
-   Currently, only table and indexes have access methods. The requirements for table
+   Currently, only tables and indexes have access methods. The requirements for table
    and index access methods are discussed in detail in <xref linkend="tableam"/> and
    <xref linkend="indexam"/> respectively.
   </para>

doc/src/sgml/ref/select_into.sgml

@@ -106,11 +106,11 @@ SELECT [ ALL | DISTINCT [ ON ( <replaceable class="parameter">expression</replac
   </para>
 
   <para>
-   In contrast to <command>CREATE TABLE AS</command> <command>SELECT
+   In contrast to <command>CREATE TABLE AS</command>, <command>SELECT
    INTO</command> does not allow to specify properties like a table's access
    method with <xref linkend="sql-createtable-method" /> or the table's
    tablespace with <xref linkend="sql-createtable-tablespace" />. Use <xref
-   linkend="sql-createtableas"/> if necessary.  Therefore the default table
+   linkend="sql-createtableas"/> if necessary.  Therefore, the default table
    access method is chosen for the new table. See <xref
    linkend="guc-default-table-access-method"/> for more information.
   </para>

doc/src/sgml/storage.sgml

@@ -189,11 +189,11 @@ there.
 </para>
 
 <para>
- Note that the following sections describe the way the builtin
+ Note that the following sections describe the behavior of the builtin
  <literal>heap</literal> <link linkend="tableam">table access method</link>,
- and the builtin <link linkend="indexam">index access methods</link> work. Due
+ and the builtin <link linkend="indexam">index access methods</link>. Due
- to the extensible nature of <productname>PostgreSQL</productname> other types
+ to the extensible nature of <productname>PostgreSQL</productname>, other
- of access method might work similar or not.
+ access methods might work differently.
 </para>
 
 <para>
@@ -703,11 +703,11 @@ erased (they will be recreated automatically as needed).
 This section provides an overview of the page format used within
 <productname>PostgreSQL</productname> tables and indexes.<footnote>
   <para>
-    Actually, neither table nor index access methods need not use this page
+    Actually, use of this page format is not required for either table or
-    format.  All the existing index methods do use this basic format, but the
+    index access methods. The <literal>heap</literal> table access method
-    data kept on index metapages usually doesn't follow the item layout
+    always uses this format.  All the existing index methods also use the
-    rules. The <literal>heap</literal> table access method also always uses
+    basic format, but the data kept on index metapages usually doesn't follow
-    this format.
+    the item layout rules.
   </para>
 </footnote>
 Sequences and <acronym>TOAST</acronym> tables are formatted just like a regular table.

doc/src/sgml/tableam.sgml

@@ -48,33 +48,33 @@
   callbacks and their behavior is defined in the
   <structname>TableAmRoutine</structname> structure (with comments inside the
   struct defining the requirements for callbacks). Most callbacks have
-  wrapper functions, which are documented for the point of view of a user,
+  wrapper functions, which are documented from the point of view of a user
-  rather than an implementor, of the table access method.  For details,
+  (rather than an implementor) of the table access method.  For details,
   please refer to the <ulink url="https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/include/access/tableam.h;hb=HEAD">
   <filename>src/include/access/tableam.h</filename></ulink> file.
  </para>
 
  <para>
-  To implement a access method, an implementor will typically need to
+  To implement an access method, an implementor will typically need to
-  implement a AM specific type of tuple table slot (see
+  implement an AM-specific type of tuple table slot (see
   <ulink url="https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/include/executor/tuptable.h;hb=HEAD">
-   <filename>src/include/executor/tuptable.h</filename></ulink>) which allows
+   <filename>src/include/executor/tuptable.h</filename></ulink>), which allows
    code outside the access method to hold references to tuples of the AM, and
    to access the columns of the tuple.
  </para>
 
  <para>
-  Currently the the way an AM actually stores data is fairly
+  Currently, the way an AM actually stores data is fairly unconstrained. For
-  unconstrained. It is e.g. possible to use postgres' shared buffer cache,
+  example, it's possible, but not required, to use postgres' shared buffer
-  but not required. In case shared buffers are used, it likely makes to
+  cache.  In case it is used, it likely makes sense to use
-  postgres' standard page layout described in <xref
+  <productname>PostgreSQL</productname>'s standard page layout as described in
-  linkend="storage-page-layout"/>.
+  <xref linkend="storage-page-layout"/>.
  </para>
 
  <para>
   One fairly large constraint of the table access method API is that,
   currently, if the AM wants to support modifications and/or indexes, it is
-  necessary that each tuple has a tuple identifier (<acronym>TID</acronym>)
+  necessary for each tuple to have a tuple identifier (<acronym>TID</acronym>)
   consisting of a block number and an item number (see also <xref
   linkend="storage-page-layout"/>).  It is not strictly necessary that the
   sub-parts of <acronym>TIDs</acronym> have the same meaning they e.g. have
@@ -83,13 +83,14 @@
  </para>
 
  <para>
-  For crash safety an AM can use postgres' <link
+  For crash safety, an AM can use postgres' <link
-  linkend="wal"><acronym>WAL</acronym></link>, or a custom approach can be
+  linkend="wal"><acronym>WAL</acronym></link>, or a custom implementation.
-  implemented.  If <acronym>WAL</acronym> is chosen, either <link
+  If <acronym>WAL</acronym> is chosen, either <link
-  linkend="generic-wal">Generic WAL Records</link> can be used &mdash; which
+  linkend="generic-wal">Generic WAL Records</link> can be used,
-  implies higher WAL volume but is easy, or a new type of
+  or a new type of <acronym>WAL</acronym> records can be implemented.
-  <acronym>WAL</acronym> records can be implemented &mdash; but that
+  Generic WAL Records are easy, but imply higher WAL volume.
-  currently requires modifications of core code (namely modifying
+  Implementation of a new type of WAL record
+  currently requires modifications to core code (specifically,
   <filename>src/include/access/rmgrlist.h</filename>).
  </para>
 
@@ -103,8 +104,8 @@
  <para>
   Any developer of a new <literal>table access method</literal> can refer to
   the existing <literal>heap</literal> implementation present in
-  <filename>src/backend/heap/heapam_handler.c</filename> for more details of
+  <filename>src/backend/heap/heapam_handler.c</filename> for details of
-  how it is implemented.
+  its implementation.
  </para>
 
 </chapter>