I am fresher and just started learning about database. But one thing strikes me, being a PL/SQL I should know all the data dictionary table, rather than relying on the options given in TOAD, SQL Developer. Like explain plan, search an object, locks, search a text in database and many more which we uses in daily life .
Can anyone contribute the tables or query which we can use in daily practices,rather than just clicking the button in tool, because it's not possible that everywhere we have this GUI interface to work with.
I think this will be very helpful for the people who really want to know what is working behind what option in our buttons.
For Example: The query below is use to search the string in all the database objects
Select *
FROM DBA_SOURCE
WHERE text LIKE '%<your text >%';
You are right: developers (and wannabe DBAs come to that) should know the Data Dictionary, rather than relying on an IDE. A good Oracle practitioner should be able to survive with just a text editor and SQL*Plus.
There are too many views to understand them all. You just need to know that they are all covered in the documentation. Find out more.
there are many different uses of the data dictionary from querying package sources, to database administration.
Burleson has a few here to get you started
http://www.dba-oracle.com/concepts/data_dictionary.htm
You can get a good list from the following select statement:
select table_name||': '||comments from dictionary;
That lists 838 rows. The ones you would use most are probably ALL_OBJECTS, ALL_TABLES, ALL_TAB_COLUMNS, ALL_VIEWS, ALL_SOURCE, ALL_COMMENTS, and (sometimes very important) ALL_SYNONYMS.
ALL_SOURCE is a good place to find documentation for Oracle's built-in packages, because the comments in the package specification tell you everything you need to know to use them. For example, look at DBMS_SQL.
Related
I need a way to search my entire Oracle database for a column that contains the value 'Beef'. What I need is the column name and table name so I can complete my query. Beef is an animal feed type and it is a known value in my database. I just don't know where.....
Essentially, we have a very old very clunky application that I am using SQL data sets generated from Toad freeware to get around. The application shows us laboratory testing information for our companies. The catch is you can only look at one company's lab report at a time, and as a I said, it takes FOREVER. We have over 700 companies we regulate so this is not an option (oh and you can't copy any of the fields).
I have already generated a query that gets me 99% of the information I need until I realized I was missing one column value that for some unearthly reason isn't included with the other attributes of the lab samples. We have around 100 or so tables and many of them aren't even in use. It's a poorly organized database and I've tried manually going through it and simply cannot find the stupid column and I have no idea what it could be named (naming conventions here seem not to apply).
A monkey wrench is: although I've done a decent amount of SQL coding for my job I'm not in IT. My job hooked me up with a read-only access of our database so I could run reports for them etc, but I'm not in the IT section so I don't get write privileges. So a lot of solutions I see that use DDL aren't available to me.
I guess it might be relevant, it looks like we're running oraClient10g.
I've tried this code that I got from here: community.Oracle
but as you can see I don't get any results.
I also tried the one suggested here at stackOverflow, but got a litany of errors so I abandoned that pretty quick. (I figured it's because of my read-only privileges and or my version of Oracle).
Any help would be greatly appreciated.
I am trying to design a database with search-ability at its core. My knowledge of database design and SQL is all self-taught and still fairly beginner-level, so my questions may possibly have easy answers.
Suppose I have a single table containing a large number of records. For example, suppose that each record contains details of a different computer application (name, developer, version number, etc). A list of keywords are associated with each record, such as a list of programming languages used to write the applications.
I wish to be able to enter one or more keywords (each separated by a space) into a search box, and I wish to have all associated records returned. How should I design the database to store the keywords, and what SQL query would I need to apply to the search text? (The search should be uppercase/lowercase independent.)
My next challenge would then be to order search results by relevance, and to allow entire key-phrases as well as keywords to be associated with each record. For example, if I type "Visual Basic" into the search field, I want the first results to have exactly the key-phrase "Visual Basic" associated with them. The next results should all have both keywords "Visual" and "Basic" associated with them, and the remaining results should have only one of these keywords. Again, please could anyone advise on how to implement this?
The final challenge I believe would be much harder: how much 'intelligent interpretation' can I design my database and SQL code to handle? For example, if I search for "CSS", can I get the records with the key-phrase "Cascading Style Sheets" to appear? Can I also get SQL to identify and search for similar words, such as plurals of search phrases or, for example, "programmer" or "programming" when "program" is input? Thanks!
Learn relational algebra, normalization rules, and SQL.
Start with entity relationships. Sounds like you could have an APPLICATION table as parent for a FEATURE child table, with a one-to-many relationship between the two. You'll query them by JOINing one to the other:
SELECT A.NAME, F.NAME
FROM APPLICATION AS A
JOIN FEATURE AS F
ON F.APP_ID = A.ID
Your challenges would not suggest SQL and relations to me. I would think more in terms of a parser, an indexer and search engine like Lucene, and a NoSQL document database like MongoDB.
I've come to the conclusion, after a LOT of research, that #duffymo's answer is hinting in the right direction. For the benefit of other n00bs like me, here's the conclusion I've drawn:
Many open source search engine server apps are out there to install for free. Lucene was the first I had ever heard of them, but others do exist and I think my favourite at the moment is Sphinx. As far as I can tell, the 'indexer' that #duffymo mentions is built into it. I have learnt that the indexer is the program that will examine my database for keywords and will automatically keep a record of which results should be returned for different input queries. I have also now learnt that the terminology for the behaviour I was looking for (and which Sphinx has) is 'stemming'. I'm still not sure what role a parser plays in all this...
A more basic approach would be to use SQL itself. Whilst I was already aware of the most basic of these (ie. using the LIKE keyword with 'wildcards'), I also discovered something a little more powerful: natural language / full-text search. For anyone not interested in installing a server app, I recommend you look this up.
Also, I see no reason why I would need to use NoSQL instead of SQL (as #duffymo has suggested), and so I'm going to stick with SQL for the moment (at least until I come across some good entry-level books to learn NoSQL from). Furthermore, I have very little intention to learn relational algebra until I know why I should and how it would be useful. The message here is that other beginners shouldn't be off-put by these things, as I don't think Sphinx requires any knowledge of them.
while I like #duffymo's answer, I will also suggest you research SPARQL and the wordnet project for your semantic equivalence questions.
If you choose Oracle, you can use the spatial option triple store to implement the SPARQL endpoint and do some very nice seaching like your css = Cascading Style Sheet example.
I would like to build arbitrary queries to a database, by allowing the user to build queries "on the fly". For every object/table, being able to select its attributes, and then "building" the query (that would translate into a SQL statement) and finally launching it, all through a web interface.
The ticketing system "rt" does that, for example, and another example would be the http://gatherer.wizards.com/Pages/Advanced.aspx webpage.
I'm currently programming in rails but any existing solution that implements this (or something similar) would be welcome.
Just be careful when creating dynamically generated queries like this that will need to be executed via sp_executesql (example: ms sql server), etc..... make sure you cover all of your bases to ensure that your application isnt vulnerable to SQL injection attacks as this type of development will essentially get one in a lot of trouble if its done incorrectly.. I would recommend storing all queries in a table and only reading queries from this table to help isolate the queries that are being ran in your application. Just identify them with a label, and allow the EU to choose the label from a dropdown list control on the frontend.
Good luck and I'm not sure of any software that will help assist
Not quite sure what your use case is here but i would say check out the
Doctrine ORM ( Object Relational Mapper )
**Edit
After reading more and looking at the example. I would only suggest Doctrine for a large website.
Then use Doctrines DQL syntax with some javascript/jquery magic for the forms.
Note that the queries you're referencing aren't arbitrary: they're on a very specific problem domain, on a specific set of sql tables.
That said, if I were you I'd look into how people are building sql queries with javascript. Something like these:
http://code.google.com/p/django-querybuilder/
http://css.dzone.com/articles/sqlike-sql-querying-engine?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+zones%2Fria+(RIA+Zone)
http://thechangelog.com/post/4914956307/rel-arel-ported-to-node-js-with-some-changes
That'll at least get you a good idea of the underlying data structures.
Can you advise on whether I can use just the Query functionality from Lucene to generate SQL queries? Something like an SQLQueryBuilder?
I have a massive SQL database of logs from a webserver cluster containing the original request and response strings plus some other useful/less bits and bobs. What I need to do is analyse the parameters in the original request and compare with the generated responses, looking at ratios, volatility, variability, consistency etc.
This question does not relate to the analysis stage, but only the retrieval of data from database which matches the parameters I'm interested in. So, I could just do this in good old sql queries, manually building the exact queries I need on a case-by-case basis. But that's kinda lame; I reckon we can be a bit smarter than that. Particularly as I can already see large numbers of similar but subtly different queries being useful. And as I'm hoping that I can expose a single search box via a web interface to non-technical end-users, adding sql queries seems like a bad idea... and a recipe for permanent maintenance requests (and can I be the first to say, er no thanks!).
In an ideal world I expose a search form, with the option to write simple queries like
request:"someAttribute=\"someValue\"" AND response="some hoped for result" AND daterange:30
which would then hopefully find all instances of requests which contain someAttribute="someValue" over the last 30 days. The results will then be put through standard statistical analyses on the given response text and printed out on-screen. At least, that's the idea.
Much of the actual logic to determine how to handle custom field definitions or special words I'll need to write myself, and that's ok. And NB, my non-technical end users are familiar enough with xml that they can handle a bit of attr="value" syntax, at least for the first iteration of the tool :D
In summary, I want to:
1) allow users to use google-like search syntax (e.g. via Lucene's QueryAPI) to specify text to match in the logs
2) allow a layer to manipulate the query based on special words or fields (e.g. this layer could be during a Java object phase)
3) convert the final query into an sql query appropriate for my database schema
4) query the database and spit back the resultset for statistical analysis
5) pretty-print on website:)
Am I completely barking up the wrong tree? It looks like it should be possible, but I can't seem to find much on it. I've been googling for a bit on this, for example trying "Lucene SQLQueryBuilder" as a possible start but didn't really find much by way of a lead.
So, my questions are:
Has anyone tried using Lucene's QueryAPI like this before? Did it work? Any gotchas?
Are there better query api libraries out there?
Examples, finished discussions and open-source implementations would be most helpful.
Many thanks.
NB: I don't think I want Lucene's search capabilities as such, as I'm only ever looking for exact matches. I just need a query layer on top of the database.
Lucene and SQL have very little in common as they're using totally different syntax (as HefferWolf mentioned) and different underlying data models. As you said yourself, I'm afraid you're barking the wrong tree.
There are however attempts, such as Hibernate Search to bridge this gap. These are interesting experiments as such, but I would be very careful to use any of that code in production.
You could possibly use Full Text Search features available in some SQL databases, or reindex all data in Lucene and use it without database.
I doubt you can reuse any code from lucene for this. Lucene does an internal rewrite of such queries but into a syntax which wouldn't be of much help for SQL I think.
name: Phil AND lastname: Miller AND NOT age: 26
would be rewritten to
+name Phil +lastname: Miller -age: 26
So I think you would have to write your on transition into a SQL Query syntax.
But maybe you can use Lucene as such for this. Have a look into hibernate-search which is quite handy to easily create a lucene index of a sql table.
Working in a team environment, each one of us has put together our own list of SQL statements that we use to help with our day to day job functions. As the case often is, there may be some redundancy with this, and we are often in need of each other's statements. To circumvent this, I'm looking to put together a small app that can be used to store and search for these SQL statements.
To begin with, I'm keeping it basic, just storing and searching the statements. This may build out to be the actual execution at some point in the future, but I'm not concerning myself with this at the time.
This will be built with PHP and MySQL - Should I store the SQL as text, or is there something that I need to be concerned with?
text should be fine.
you will also want a name (label) and possibly a descriptive field to let people know what it does in plain english.
Any particular reason these aren't just stored in the database as stored procedures?
Or in your version control system as scripts?