I'm running a website for a jewellery wholesaler.
The prices on all their products are calculated using the current bullion metal fixes that are updated every night.
Currently, for the website, the calculations are worked out via a php include function, which works fine under current circumstances.
There are around 10,000 products, but the prices are calculated in real-time (ie when the web page is requested). The calculations are simple, but there are lots of them (Around 50+) and i'm worried that an increase in traffic may slow the current script down.
I'm redesigning the site and was wondering whether it would be beneficial to create a procedure in MySQL to do the calculations instead.
Is this likely to be faster that the current php script?
Anyone know any good reading reference on using procedures?
Here's a benchmark with stored procedure vs php.
http://mtocker.livejournal.com/45222.html
The stored procedure was slower by 10x.
You might also want to look at this:
http://www.tonymarston.net/php-mysql/stored-procedures-are-evil.html
If the reason you are thinking about this is due to performance and scalability, then I would recommend continuing the calculation in PHP.
The reason for this is that regardless whether there is a performance penalty in your PHP, when you are scaling your web application it is generally much easier to move to multiple web servers than multiple database servers. It is therefore preferable to do more calculation in PHP and less in MySQL.
Other than the performance aspect, I still generally prefer avoiding stored procedures in favour of having the logic in the application because
It can be less portable. Stored procedure add to the effort required to deploy a new instance of your application.
They are written in a different language than PHP, so a PHP developer may not find them easy to understand.
It can be difficult to have them kept in source control.
These problems can of course all be solved, without too much difficulty, but it all adds to the complexity overhead.
If it is absolutely necessary to update the prices on every page request and you're worried that the site will be getting a lot of traffic I wouldn't recommend stored procedures.
I'd recommend caching the information you use (and it is hard to elaborate without knowing how you're doing this) in memory (perhaps using memcached) and keep reading it from PHP.
I'll admit that I haven't done any benchmarking between stored procedures vs in-memory PHP performance but if the procedure doesn't directly affect your query, I recommend caching.
In short, keep them in php. Easier to maintain.
For the current site, there is unlikely to ever hit a performance problem where the difference between the speed of calc in php vs the speed of the calc in the database is ever noticeable. If you were then there is something fundamentally wrong with the code of the site. (This includes realtime currency conversions if being done).
Saying that, keeping the calc in PHP is usually preferred as it is easier to control and debug. It does require the web coders to know the database somewhat but that is normally not a problem. 90% of the code speed ups happen on 10% of the code and it would be easy enough for a dba to identify the queries causing db load if it ever happened.
Related
We are at the beginning of a new project, and we are really wondering if we should use stored procedures in MySQL or not.
We would use the stored procedures only to insert and update business model entities. There are several tables which represent a model entity, and we would abstract it in those stored procedures insert/update.
On the other hand, we can call insert and update from the Model layer but not in MySQL but in PHP.
In your experience, Which is the best option? advantages and disadvantages of both approaches. Which is the fastest one in terms of high performance?
PS: It is is a web project with mostly read and high performance is the most important requisite.
Unlike actual programming language code, they:
not portable (every db has its own version of PL/SQL. Sometimes different versions of the same database are incompatible - I've seen it!)
not easily testable - you need a real (dev) database instance to test them and thus unit testing their code as part of a build is virtually impossible
not easily updatable/releasable - you must drop/create them, ie modify the production db to release them
do not have library support (why write code when someone else has)
are not easily integratable with other technologies (try calling a web service from them)
they use a language about as primitive as Fortran and thus are inelegant and laborious to get useful coding done, so it is difficult to express business logic, even though typically that is what their primary purpose is
do not offer debugging/tracing/message-logging etc (some dbs may support this - I haven't seen it though)
lack a decent IDE to help with syntax and linking to other existing procedures (eg like Eclipse does for java)
people skilled in coding them are rarer and more expensive than app coders
their "high performance" is a myth, because they execute on the database server they usually increase the db server load, so using them will usually reduce your maximum transaction throughput
inability to efficiently share constants (normally solved by creating a table and questing it from within your procedure - very inefficient)
etc.
If you have a very database-specific action (eg an in-transaction action to maintain db integrity), or keep your procedures very atomic and simple, perhaps you might consider them.
Caution is advised when specifying "high performance" up front. It often leads to poor choices at the expense of good design and it will bite you much sooner than you think.
Use stored procedures at your own peril (from someone who's been there and never wants to go back). My recommendation is to avoid them like the plague.
Unlike programming code, they:
render SQL injection attacks almost
impossible (unless you are are
constructing and executing dynamic
SQL from within your procedures)
require far less data to be sent over
the IPC as part of the callout
enable the database to far better
cache plans and result sets (this is
admittedly not so effective with
MySQL due to its internal caching
structures)
are easily testable in isolation
(i.e. not as part of JUnit tests)
are portable in the sense that they
allow you to use db-specific
features, abstracted away behind a
procedure name (in code you are stuck
with generic SQL-type stuff)
are almost never slower than SQL
called from code
but, as Bohemian says, there are plenty of cons as well (this is just by way of offering another perspectve). You'll have to perhaps benchmark before you decide what's best for you.
As for performances, they have the potential to be really performant in a future MySQL version (under SQL Server or Oracle, they are a real treat!). Yet, for all the rest... They totally blow up competition. I'll summarize:
Security: You can give your app the EXECUTE right only, everything is fine. Your SP will insert update select ..., with no possible leak of any sort. It means global control over your model, and an enforced data security.
Security 2: I know it's rare, but sometimes php code leaks out from the server (i.e. becomes visible to public). If it includes your queries, possible attackers know your model. This is pretty odd but I wanted to signal it anyway
Task force: yes, creating efficient SQL SPs requires some specific resources, sometimes more expensive. But if you think you don't need these resources just because you're integrating your queries in your client... you're going to have serious problems. I'd mention the analogy of web development: it's good to separate the view from the rest because your designer can work on their own technology while the programmers can focus on programming the business layer.
Encapsulating business layer: using stored procedures totally isolates the business where it belongs: the damn database.
Quickly testable: one command line under your shell and your code is tested.
Independence from the client technology: if tomorrow you'd like to switch from php to something else, no problem. Ok, just storing these SQL in a separate file would do the trick too, that's right. Also, good point in the comments about if you decide to switch sql engines, you'd have a lot of work to do. You have to have a good reason to do that anyway, because for big projects and big companies, that rarely happens (due to the cost and HR management mostly)
Enforcing agile 3+-tier developments: if your database is not on the same server than your client code, you may have different servers but only one for the database. In that case, you don't have to upgrade any of your php servers when you need to change the SQL related code.
Ok, I think that's the most important thing I had to say on the subject. I developed in both spirits (SP vs client) and I really, really love the SP style one. I just wished Mysql had a real IDE for them because right now it's kind of a pain in the ass limited.
Stored procedures are good to use because they keep your queries organized and allow you to perform a batch at once. Stored procedures are normally quick in execution because they are pre-compiled, unlike queries that are compiled on every run. This has significant impact in situations where database is on a remote server; if queries are in a PHP script, there are multiple communication between the application and the database server - the query is send, executed, and result thrown back. However, if using stored procedures, it only need to send a small CALL statement instead of big, complicated queries.
It might take a while to adapt to programming a stored procedure because they have their own language and syntaxes. But once you are used to it, you'll see that your code is really clean.
In terms of performance, it might not be any significant gain if you use stored procedures or not.
I will let know my opinion, despite my toughts possibly are not directly related to the question.:
As in many issues, reply about using Stored Procedures or an application-layer driven solution relies on questions that will drive the overall effort:
What you want to get.
Are you trying to do either batch operations or on-line operations? are they completely transactional? how recurrent are those operations? how heavy is the awaited workload for the database?
What you have in order to get it.
What kind of database technology you have? What kind of infrastucture? Is your team fully trained in the database technology? Is your team better capable of building a database-aegnostic solution?
Time for get it.
No secrets about that.
Architecture.
Is your solution required to be distributed onto several locations? is your solution required to use remote communications? is your solution working on several database servers, or possibly using a cluster-based architecture?
Mainteinance.
How much is the application required to change? do you have personal specifically trained for maintain the solution?
Change Management.
Do you see your database technology will change at a short, middle, long time? do you see will be required to migrate the solution frequently?
Cost
How much will cost to implement that solution using one or another strategy?
The overall of those points will drive the answer. So you have to care each of this points when making a decision about using or not any strategy. There are cases where using of stored procedures are better than application-layer managed queries, and others when, conducting queries and using an application-layer based solution is best.
Using of stored procedures tends to be more addequate when:
Your database technology isn't provided to change at a short time.
Your database technology can handle parallelized operations, table partitions or anything else strategy for divide the workload onto several processors, memory and resources (clustering, grid).
Your database technology is fully integrated with the stored proceduce definition language, that is, support is inside the database engine.
You have a development team who aren't afraid about using a procedural language (3rd. Generation language) for getting a result.
Operations you wanna achieve are built-in or supported inside the database (Exporting to XML data, managing data integrity and coherence appropiately with triggers, scheduled operations, etc).
Portability isn't an important issue and you do not whatch a technology change at a short time into your organization, even, it is not desirable. Generally, portability is seen like a milestone by the application-driven and layered-oriented developers. From my point of view, portability isn't an issue when your application isn't required to be deployed for several platforms, less when there are no reasons for making a technology change, or the effort for migrating all the organizational data is higher than the benefit for making a change. What you can win by using an application-layer driven approach (portability) you can loose in performance and value obtained from your database (Why to spend thousands of dollars for to get a Ferrari that you'll drive no more than 60 milles/hr?).
Performance is an issue. First: In several cases, you can achieve better results by using a single stored procedure call than multiple requests for data from another application. Moreover, some characteristics you need to perform may be built-in your database and its use less expensive in terms of workload. When you use an application-layer driven solution you have to take in account the cost associated to make database connections, making calls to the database, network traffic, data wrapping (i.e., using either Java or .NET, there is an implicit cost when using JDBC/ADO.NET calls as you have to wrap your data into objects that represents the database data, so instantiation has an associated cost in terms of processing, memory, and network when data comes from and goes to outside).
Using of application-layer driven solutions tends to be more addequate when:
Portability is an important issue.
Application will be deployed onto several locations with only one or few database repositories.
Your application will use heavy business-oriented rules, that need to be agnostic of the underlying database technology.
You have in mind to do change technology providers based on market tendencies and budget.
Your database isn't fully integrated with the stored procedure language that calls to the database.
Your database capabilities are limited and your requirement goes beyond what you can achieve with your database technology.
Your application can support the penalty inherent to external calls, is more transactional-based with business-specific rules and has to abstract the database model onto a business model for the users.
Parallelizing database operations isn't important, moreover, your database has not parallelization capabilities.
You have a development team which is not well-trained onto the database technology and is better productive by using an application-driven based technology.
Hope this may help to anyone asking himself/herself what is better to use.
I would recommend you don't use stored procedures:
Their language in MySQL is very crappy
There is no way to send arrays, lists, or other types of data structure into a stored procedure
A stored procedure cannot ever change its interface; MySQL permits neither named nor optional parameters
It makes deploying new versions of your application more complicated - say you have 10x application servers and 2 databases, which do you update first?
Your developers all need to learn and understand the stored procedure language - which is very crap (as I mentioned before)
Instead, I recommend to create a layer / library and put all your queries in there
You can
Update this library and ship it on your app servers with your app
Have rich data types, such as arrays, structures etc passed around
Unit test this library, instead of the stored procedures.
On performance:
Using stored procedures will decrease the performance of your application developers, which is the main thing you care about.
It is extremely difficult to identify performance problems within a complicated stored procedure (it is much easier for plain queries)
You can submit a query batch in a single chunk over the wire (if CLIENT_MULTI_STATEMENTS flag is enabled), which means you don't get any more latency without stored procedures.
Application-side code generally scales better than database-side code
If your database is complex and not a forum type with responses, but true warehousing SP will definitely benefit. You can out all your business logic in there and not a single developer is going to care about it, they just call your SP's. I have been doing this joining over 15 tables is not fun, and you cannot explain this to a new developer.
Developers also don't have access to a DB, great! Leave that up to database designers and maintainers. If you also decide that the table structure is going to get changed, you can hide this behind your interface. n-Tier, remember??
High performance and relational DB's is not something that goes together, not even with MySQL InnoDB is slow, MyISAM should be thrown out of the window by now. If you need performance with a web-app, you need proper cache, memcache or others.
in your case, because you mentioned 'Web' I would not use stored procedures, if it was data warehouse I would definitely consider it (we use SP's for our warehouse).
Tip:
Since you mentioned Web-project, ever though about nosql sort of solution? Also, you need a fast DB, why not use PostgreSQL? (trying to advocate here...)
I used to use MySql and my understanding of sql was poor at best, I spent a fair amount of time using Sql Server, I have a clear separation of a data layer and an application layer, I currently look after a server with 0.5 terabytes.
I have felt frustrated at times not using an ORM as development is really quick with stored procedures it is much slower. I think much of our work could have been sped up by using an ORM.
When your application reaches critical mass, the ORM performance will suffer, a well written stored procedure, will give you your results faster.
As an example of performance I collect 10 different types of data in an application, then convert that to XML, which I process in the stored procedure, I have one call to the database rather than 10.
Sql is really good at dealing with sets of data, one thing that gets me frustrated is when I see someone getting data from sql in a raw form and using application code to loop over the results and format and group them, this really is bad practice.
My advice is to learn and understand sql enough and your applications will really benefit.
Lots of info here to confuse people, software development is a evolutionary. What we did 20 years ago isn't best practice now. Back in the day with classic client server you wouldnt dream of anything but SPs.
It is absolutely horses for courses, if you are a big organisation with you will use multi tier, and probably SPs but you will care little about them because a dedicated team will be sorting them out.
The opposite which is where I find myself trying to quickly knock up a web app solution, that fleshes out business requirements, it was super fast to leave the developer (remote to me) to knock up the pages and SQL queries and I define the DB structure.
However complexity is growing and without an easy way to provide APIs, I am staring to use SPs to contain the business logic. I think it is working well and sensible, I control this because I can build logic and provide a simple result set for my offshore developer to build a front end around.
Should I find my software a phenomenal success, then more separation of concerns will occur and different implementations of n teir will come about but for now SPs are perfect.
You should know all the tool sets available to you and match them is wise to start with. Unless you are building an enterprise system to start with then fast and simple is best.
I would recommend that you stay away from DB specific Stored Procedures.
I've been through a lot of projects where they suddently want to switch DB platform and the code inside a SP is usually not very portable = extra work and possible errors.
Stored Procedure development also requires the developer to have access directly to the SQL-engine, where as a normal connection can be changed by anyone in the project with code-access only.
Regarding your Model/layer/tier idea: yes, stick with that.
Website calls Business layer (BL)
BL calls Data layer (DL)
DL calls whatever storage (SQL, XML, Webservice, Sockets, Textfiles etc.)
This way you can maintain the logic level between tiers. IF and ONLY IF the DL calls seems to be very slow, you can start to fiddle around with Stored Procedures, but maintain the original none-SP code somewhere, if you suddently need to transfer the DB to a whole new platform. With all the Cloud-hosting in the business, you never know whats going to be the next DB platform...
I keep a close eye on Amazon AWS of the very same reason.
I think there is a lot of misinformation floating around about database stored queries.
I would recommend using MySQL Stored Procedures if you're doing many static queries for data manipulation. Especially if you're moving things from one table to another (i.e. moving from a live table to a historical table for whatever reason). There are drawbacks of course in that you'll have to keep a separate log of changes to them (you could in theory make a table that just holds changes to the stored procedures that the DBA's update). If you have many different applications interfacing with the database, especially if say you have a desktop program written in C# and a web program in PHP, it might be more beneficial to have some of your procedures stored in the database as they are platform independent.
This website has some interesting information on it you may find useful.
https://www.sitepoint.com/stored-procedures-mysql-php/
As always, build in a sandbox first, and test.
Try to update 100,000,000 records on a live system from a framework, and let me know how it goes. For small apps, SPs are not a must, but for large serious systems, they are a real asset.
I am developing an auction site that requires maintenance scripts to be run in the background to ensure smooth running. Things such as ending auctions, starting auctions, etc...
There seem to be many options and no definite answers when I research the subject.
Is there a standard for doing this sort of thing? My research so far has uncovered these possibilities:
PHP and CRON, too slow, no evidence of anyone else using this method?
MYSQL stored procedures: don't want to deal with MYSQL language
BASH script???
C script???
I hope that someone with experience can inform me of pros and cons that I am missing, other things to think about when deciding which method to use, etc...
Speed (and efficiency) are very important.
Thanks!
I have a site that does some pretty intensive maintenance using PHP + Cron. I would recommend that since you can reuse libraries from the main application. In what way is php too slow?
Unless you doing som serious number crunching in the application, most of the burden is on the database. In that case only Bash/cscript would have worse performance than php.
This might be more of a http://serverfault.com question.
If you need something custom because the above won't work for you, pick something that uses the technologies you already have libraries and things written in, i.e. perl, python, C, php, whatever (so that you don't have to port work you've already had to do, if you need to expand it later to access things before making timing decisions), and write a custom program that does it for you. Then have cron make sure that it's always up, and it can do the more time-intensive things itself rather than in cron.
I have developed and manage a massive database system with 700+ databases [don't ask...], which need plenty of maintenance in terms of updates, summaries, synchronisation of structures, etc.
All of this is done through Bash and PHP scripts running regularly through cron. Some every 10 minutes, some hourly, some daily, some monthly - never have I had any issues with speed / performance, so long as you code the scripts and SQL statements so that they are efficient when run!
One of the most important things is to tune your MySQL indexes to ensure that your regular scheduled jobs run quickly, minimising the regular CPU hits that occur when the cron's run.
Is it considered crazy to store common SQL queries for my web app in a database for use in execution? Or is that common practice? Or is it impossible?
My thinking is, this way, I avoid hard-coding SQL into my application files, and add another level of abstraction.
Is this crazy? Is this what a stored procedure is? Or is that something else?
EDIT: The below answers are useful as a background for 'stored procedures', but didn't answer my core question: Is a 'stored procedure' just when I have a database table that contains queries that can be called? ie, something like this
INDEX | NAME | QUERY
1 | show_names | "SELECT names.first, names.last FROM names;"
2 | show_5_cities | "SELECT cities.city FROM cities LIMIT 0,5;"
etc.
Or is there a more complicated mechanism that encompasses the concept of stored procedures? Is my example an actual example of something people do?
Along with MUG4N's great reasons on why to use stored procedures, here are three more:
Security
You can grant access to your application to execute stored procedures while denying direct table access.
Think defense in depth. If your app is cracked, then they will be limited to executing ONLY the procedures you have defined. This means things like 'drop table' would be explicitly disallowed, unless, of course, you have a procedure to do that.
Conversely, if your app is cracked and you allow the app to have full access to your sql server, then one of two things will happen. Either your data disappears and/or the cracker easily get's a copy.
Unit Testing.
It's much easier to unit test your queries if you can hit them directly without having to go through the application itself.
In Flight Changes:
If you need to modify a query AFTER you have published your site, it's much easier to just make a proc change than redeploy code that may have undergone other changes since the last deployment. For example, let's say you have a page that isn't performing all that well. After evaluation, you determine that just changing the joins on a query will fix this. Modify the proc and go.
Well in my opinion you should definitly use stored procedures. And this is common practice!
Here are just two advantages of using stored procedures:
They will run in all environments, and there is no need to recreate the logic. Since they are on the database server, it makes no difference what application environment is used - the stored procedure remains consistent. If your setup involves different clients, different programming languages - the logic remains in one place. Web developers typically make less use of this feature, since the web server and database server are usually closely linked. However, in complex client-server setups, this is a big advantage. The clients are automatically always in sync with the procedure logic as soon as its been updated.
They can reduce network traffic. Complex, repetitive tasks may require getting results, applying some logic to them, and using this to get more results. If this only has to be done on the database server, there is no need to send result sets and new queries back and forth from application server to database server. Network traffic is a common bottleneck causing performance issues, and stored procedures can help reduce this. More often though, it is the database server itself that is the bottleneck, so this may not be much of an advantage.
The idea certainly has its appeal -- but the problems is, they are nearly impossible to scale.. I have never seen a scalable solution to maintaining stored procs (especially in MySQL) that has not made me shutter.
Since it seems you're heading the PHP/MySQL route, I'll give a few examples of my experience with stored procs in MySQL:
They are generally far less readable and far more difficult to write than PHP.
They make debugging a nightmare
Trying to figure out why changing a value in table_1 triggers a change in table_2 (if you're even lucky enough to recognize that this happens) is much more difficult to determine by looking through dozens of stored procedures than it is to, say, look in the Model that handles changes to table_1.
To my knowledge there is no standardized & automated way to integrate stored procs / triggers / etc into any revision control system
A stored procedure is just one or more SQL statements that are "pre-compiled" and live inside the database. You call them to return one or more rows of data, or to update, insert, or delete data.
If you tell us what web framework and database you are using, we can give you actual examples of how to call a stored procedure, or at least point you to an article or two to get you going.
You could also consider using an ORM framework, such as Hibernate. This will allow you to get away from dealing with SQL code altogether. I am a .Net developer, so I'm not sure what is available to you on the PHP/MySQL platform, but I am sure there is a lot out there to choose from.
You should think about it, when developing a commercial grade tiered application there is always people behind the database making it secure and reliable, other people are behind the application logic and other people behind the web code, so you can get the best of all working together.
Once the application has been designed, everyone start making their implementations, the db people give to the others some kind of API to use hiding the SQL, the developers won't have to think about it and focus on their code, i had worked as db developer and used some COM techniques to overcome the expansion and modification of the application logic or reuse, the database in these kind of products is too important to leave it in the wild so security it's a really serious issue.
But in most cases, web applications are made by web developers and they tend to have no design time, making big changes on the near time so they don't use stored procedures, also they don't even secure execution or try to leave security to the application leaving the database unprotected and prone to attacks.
If you're doing everything and changing your product too often you should avoid them since it will be double work and most of the times will be useless, once you stabilize your logic then you could start migrating your heavier queries to stored procedures.
My webapp that I am developing will incorporate a forum (phpbb3 or smf), a wiki (doku wiki flat file storage), and my main web app.
All of these will share a User table. The forum I expect to see moderate usage (roughly 200 posts a day) to begin with and will increase from there. The main web app will be used heavily with triggers, mysql events, and stored procedures.
Would splitting the forum and main web app up into separate databases be the wiser choice (IE maintainability and performance)?
Why would you ever use two databases? What possible reason can there be? Please update the question to explain why you think two databases has some advantage over one database.
Generally, everyone tries to use one database to keep the management overhead down to an acceptable level. Why add complexity?
Keep your app simple to begin with. If you're not expecting a huge amount of traffic to begin with, then it's fine to have a single database. You can always upgrade your site later. Changing which database a table is stored in shouldn't require a huge amount of code.
It depends. If there is any chance of optimization, then splitting is good not otherwise. Another thing is that even if you split, you should be able to manage them all successfully, a bit of overhead.
For the sake of maintainability in the future, I would definitely recommend against splitting DBs when you have a shared table. This will only serve to increase the size of your queries (since joins across DBs will require further qualification). This also will eventually lead to confusion when someone new can't figure out why their query doesn't work.
Furthermore, if the two DBs are actually running on separate servers or instances, you won't be able to join and will be forced to move back and forth between code and query to do something that would otherwise be a simple join. That may not be a big deal for a simple one row look up type queries, but for more complicated summary type queries, it means dumping off a lot of the processing that RDBMs' are specifically optimized for into your more general purpose programming language.
separating to two database could not guarantee performance. putting tables in different tablespace (i.e. different drives) could boost performance, as independent queries doesn't often compete for hard disk's read/write head's access turns
I'm working on a Java based project that has a client program which needs to connect to a MySQL database on a remote server. This was implemented is as follows:
Use JDBC to write the SQL queries to be executed which are then hosted as a servlet using Apache Tomcat and made accessible via XML-RPC. The client code uses XML-RPC to remotely execute these JDBC based functions. This allows us to keep our MySQL database non-public, restricts use to the pre-defined functions, and allows Tomcat to manage the database transactions (which I've been told is better than letting MySQL do it alone, but I really don't understand why). However, this approach requires a lot of boiler-plate code, and Tomcat is a huge memory hog on our server.
I'm looking for a better way to do this. One way I'm considering is to make the MySQL database publicly accessible, re-writing the JDBC based code as stored procedures, and restricting public use to these procedures only. The problem I see with this are that translating all the JDBC code to stored procedures will be difficult and time consuming. I'm also not too familiar with MySQL's permissions. Can one grant access to a stored procedure which performs select statements on a table, but also deny arbitrary select statements on that same table?
Any other ideas are welcome, as are thoughts and or sugguestions on the stored procedure solution.
Thank you!
You can probably get the RAM upgraded in your server for less than the cost of even a few days development time, so don't write any code if that's all you're getting from the exercise. Also, just because the memory is used inside of tomcat, it doesn't mean that tomcat itself is using it. The memory could be used up by data or by technical flaws in your code.
If you've tried additional RAM and it is being eaten up, then that smells like a coding issue, so I'd suggest using a profiler, or log data to try and work out what the root cause is before changing anything. If the cause is large data sets then using the database directly will only delay the inevitable, instead you'd need to look at things like paging, summarisation, client side caching, or redesigning clients to reduce the use of expensive queries. Using a profiler, or simply reviewing the code base, will also tell you if something is creating too many objects (especially strings, or XML nodes) or leaking memory.
Boiler plate code can be avoided by refactoring creatively, and its good that you do avoid repetition. Its unclear how much structure you might already have, but with a little work its easy to centralise boilerplate JDBCs calls. There is no fundamental reason JDBC code should be repeated, perhaps you could tell us what code is being repeated?
Finally, I'll venture that there are many good reasons to put a web tier over your database. Flexibility (of deployment), compatibility, control (over the SQL) and security are all good reasons to keep the web tier.
MySQL 5.0.3+ does have an execute privilege that you can set (without setting select privileges) that should allow you to get the functionality you seek.
However, note this mysql bug report with JDBC (well and a lot of other drivers).
When calling the [procedure] with JDBC, I get "java.sql.SQLException: Driver requires
declaration of procedure to either contain a '\nbegin' or '\n' to follow argument
declaration, or SELECT privilege on mysql.proc to parse column types."
the workaround is:
See "noAccessToProcedureBodies" in /J 5.0.3 for a somewhat hackish, non-JDBC compliant
workaround.
I am sure you could implement your solution without much boiler-plate, esp. using something like Spring's remoting. Also, how much memory is Tomcat eating? I frankly believe that if it's just doing what you are describing, it could work in less than 128mb (conservative guess).
Your alternative is the "correct by the book" way of solving the problem. I say build a prototype and see how it works. The major problems you could have are:
MySQL having some important gotcha in this regard
MySQL's Stored Procedure support being too primitive and forcing you to do a lot of work
Some other strange hiccup
I'm probably one of those MySQL haters, so the situation might be better than I think.