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@ -29,12 +29,13 @@ Questions answered: |
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1.8) What documentation is available for PostgreSQL? |
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1.9) What version of SQL does PostgreSQL use? |
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1.10) Does PostgreSQL work with databases from earlier versions of |
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postgres? |
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PostgreSQL? |
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1.11) Are there ODBC drivers for PostgreSQL? |
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1.12) What tools are available for hooking postgres to Web pages? |
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1.12) What tools are available for hooking PostgreSQL to Web pages? |
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1.13) Does PostgreSQL have a graphical user interface? A report |
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generator? A embedded query language interface? |
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1.14) What is a good book to learn SQL? |
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1.15) What languages are available to communicate with PostgreSQL? |
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2) Installation/Configuration questions |
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@ -85,7 +86,7 @@ Questions answered: |
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database? |
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3.19) What is the time-warp feature and how does it relate to vacuum? |
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3.20) What is an oid? What is a tid? |
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3.21) What is the meaning of some of the terms used in Postgres? |
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3.21) What is the meaning of some of the terms used in PostgreSQL? |
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3.22) What is Genetic Query Optimization? |
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3.23) How do you remove a column from a table? |
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3.24) How do SELECT only the first few rows of a query? |
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@ -263,7 +264,7 @@ Section 1: General Questions |
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particularly important. |
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The www page contains pointers to an implementation guide and five |
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papers written about postgres design concepts and features. |
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papers written about Postgres design concepts and features. |
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1.9) What version of SQL does PostgreSQL use? |
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@ -275,7 +276,8 @@ Section 1: General Questions |
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On the other hand, you get to create user-defined types, functions, |
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inheritance etc. |
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1.10) Does PostgreSQL work with databases from earlier versions of postgres? |
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1.10) Does PostgreSQL work with databases from earlier versions of |
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PostgreSQL? |
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PostgreSQL v1.09 is compatible with databases created with v1.01. |
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@ -306,14 +308,14 @@ Section 1: General Questions |
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OpenLink ODBC is very popular. You can get it from |
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http://www.openlinksw.com/postgres.html. It works with our standard |
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ODBC client software so you'll have Postgres ODBC available on every |
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ODBC client software so you'll have PostgreSQL ODBC available on every |
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client platform we support (Win, Mac, Unix, VMS). |
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We will probably be selling this product to people who need |
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commercial-quality support, but a freeware version will always be |
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available. Questions to postgres95@openlink.co.uk. |
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1.12) What tools are available for hooking postgres to Web pages? |
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1.12) What tools are available for hooking PostgreSQL to Web pages? |
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A nice introduction to Database-backed Web pages can be seen at: |
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http://www.webtools.com |
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@ -341,6 +343,19 @@ Section 1: General Questions |
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Many of our users like The Practical SQL Handbook, Bowman et al, |
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Addison Wesley. |
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1.15) What languages are available to communicate with PostgreSQL? |
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We have: |
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* C(interfaces/libpq) |
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* C++(interfaces/libpq++) |
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* Embedded C(interfaces/ecpg) |
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* Java(interfaces/jdbc) |
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* Perl(interfaces/perl5) |
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* ODBC(interfaces/odbc) |
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* Python(interfaces/python) |
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* TCL(interfaces/libpgtcl) |
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* A crude C/4GL(contrib/pginterface) |
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_________________________________________________________________ |
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Section 2: Installation Questions |
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@ -576,7 +591,7 @@ Section 3: PostgreSQL Features |
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See the create_index manual page for information on what type classes |
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are available. It must match the field type. |
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Postgres does not warn the user when the improper index is created. |
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PostgreSQL does not warn the user when the improper index is created. |
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Indexes not used for ORDER BY operations. |
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@ -624,7 +639,7 @@ BYTEA bytea variable-length array of bytes |
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3.15) How do I create a serial field? |
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Postgres does not allow the user to specifiy a user column as type |
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PostgreSQL does not allow the user to specifiy a user column as type |
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SERIAL. Instead, you can use each row's oid field as a unique value. |
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However, if you need to dump and reload the database, you need to use |
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pgdump's -o option or COPY's WITH OIDS option to preserver the oids. |
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@ -687,14 +702,15 @@ BYTEA bytea variable-length array of bytes |
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3.20) What is an oid? What is a tid? |
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Oids are Postgres's answer to unique row ids or serial columns. Every |
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row that is created in Postgres gets a unique oid. All oids generated |
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by initdb are less than 16384 (from backend/access/transam.h). All |
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post-initdb (user-created) oids are equal or greater that this. All |
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these oids are unique not only within a table, or database, but unique |
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within the entire postgres installation. |
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Oids are PostgreSQL's answer to unique row ids or serial columns. |
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Every row that is created in PostgreSQL gets a unique oid. All oids |
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generated by initdb are less than 16384 (from |
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backend/access/transam.h). All post-initdb (user-created) oids are |
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equal or greater that this. All these oids are unique not only within |
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a table, or database, but unique within the entire PostgreSQL |
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installation. |
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Postgres uses oids in its internal system tables to link rows in |
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PostgreSQL uses oids in its internal system tables to link rows in |
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separate tables. These oids can be used to identify specific user rows |
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and used in joins. It is recommended you use column type oid to store |
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oid values. See the sql(l) manual page to see the other internal |
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@ -705,7 +721,7 @@ BYTEA bytea variable-length array of bytes |
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are used by index entries to point to physical rows. They can not be |
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accessed through sql. |
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3.21) What is the meaning of some of the terms used in Postgres? |
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3.21) What is the meaning of some of the terms used in PostgreSQL? |
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Some of the source code and older documentation use terms that have |
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more common usage. Here are some: |
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