Re: PostgreSQL and SOAP, suggestions?

That function looks great, but what happens if you need to return 1
million records? Wouldn't you exhaust all the memory in the server? Or
can you stream it somehow?

I have an actual libpq program which performs a query against a server,
and will stream out the XML, so the number of records has very little
affect on efficiency. I think the table2xml function is great for 99% of
all the queries, but for those huge resultsets, I think it may be
problematic.

What do you think?

BTW, I routinely have queries that return millions of rows.

Peter Eisentraut wrote:

>mlw writes:
>
>
>
>>Given a HTTP formatted query:
>>GET "http://localhost:8181/pgmuze?query=select+*+from+zsong+limit+2"
>>
>>The output is entered below.
>>
>>
>
>That looks a lot like the SQL/XML-style output plus a SOAP header. Below
>is the output that I get from the SQL/XML function that I wrote. A simple
>XSLT stylesheet should do the trick for you.
>
>Btw., I also have an XSLT stylesheet that can make an HTML table out of
>this output and I have a table function that can generate a virtual table
>from this output.
>
>
>=> select table2xml('select * from products');
>
><?xml version='1.0'?>
><table
> xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
> xsi:noNamespaceSchemaLocation='#'> <!-- XXX this needs to be fixed -->
>
><xsd:schema
> xmlns:xsd='http://www.w3.org/2001/XMLSchema'
> xmlns:sqlxml='http://www.iso-standards.org/mra/9075/2001/12/sqlxml'>
>
> <xsd:import
> namespace='http://www.iso-standards.org/mra/9075/2001/12/sqlxml'
> schemaLocation='http://www.iso-standards.org/mra/9075/2001/12/sqlxml.xsd' />
>
><xsd:simpleType name='peter.pg_catalog.text'>
> <xsd:restriction base='xsd:string'>
> <xsd:maxLength value='MLIT' /> <!-- XXX needs actual value -->
> </xsd:restriction>
></xsd:simpleType>
>
><xsd:simpleType name='INTEGER'>
> <xsd:restriction base='xsd:integer'>
> <xsd:maxInclusive value='2147483647'/>
> <xsd:minInclusive value='-2147483648'/>
> </xsd:restriction>
></xsd:simpleType>
>
><xsd:simpleType name='NUMERIC'>
> <xsd:restriction base='xsd:decimal'>
> <xsd:totalDigits value='PLIT'/> <!-- XXX needs actual values -->
> <xsd:fractionDigits value='SLIT'/>
> </xsd:restriction>
></xsd:simpleType>
>
><xsd:complexType name='RowType'>
> <xsd:sequence>
> <xsd:element name='name' type='peter.pg_catalog.text' nillable='true'></xsd:element>
> <xsd:element name='category' type='INTEGER' nillable='true'></xsd:element>
> <xsd:element name='price' type='NUMERIC' nillable='true'></xsd:element>
> </xsd:sequence>
></xsd:complexType>
>
><xsd:complexType name='TableType'>
> <xsd:sequence>
> <xsd:element name='row' type='RowType' minOccurs='0' maxOccurs='unbounded' />
> </xsd:sequence>
></xsd:complexType>
>
><xsd:element name='table' type='TableType' />
>
></xsd:schema>
>
> <row>
> <name>screwdriver</name>
> <category>3</category>
> <price>7.99</price>
> </row>
>
> <row>
> <name>drill</name>
> <category>9</category>
> <price>12.49</price>
> </row>
>
></table>
>
>
>