Re: [orientdb] What does this crc check is failed error mean?
Hi, you should not typical worry about it, we have 2 master records in operation log, if one is broken second one is used. Usually it only affects data restore after crash and you should worry about this exception if both master records will be broken. Master records contain information of position in operation log from which data should be restored. On Sat, Aug 9, 2014 at 3:34 AM, Jing Chen jingjing...@gmail.com wrote: Hi there, I noticed this error in the OrientDB server log today when I was loading data to the database: 2014-08-08 11:09:42:355 SEVE Can not restore 0 WAL master record for storage ndex crc check is failed [OWriteAheadLog] What does this error mean? Should I worry about the data being loaded? My Java application connects to the server through a remote connection and insert data to the database through Orientdb Graph API. I didn't get any exception from my Java program during the insert. Should this error throw an exception in the client? Thanks, Jing -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- Best regards, Andrey Lomakin. Orient Technologies the Company behind OrientDB -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[orientdb] Question on traverse with graph DB
Hi, I just learned about and started experimenting with OrientDB (1.7.7 community) a few days ago. I am very impressed. I apologize if this is a newbie question, however, I am having trouble understanding traverse with a graph DB. Steps: 1. Create a new plocal graph database 2. create three vertices: #9:0, #9:1, #9:2 just using create vertex V 3. create three edges: 1. create edge E from #9:0 to #9:1 2. create edge E from #9:1 to #9:2 3. create edge E from #9:2 to #9:3 4. select from V: +++ # |@RID|out_|in_ +++ 0 |#9:0|#9:1|null 1 |#9:1|#9:2|#9:0 2 |#9:2|null|#9:1 +++ 5. traverse V.out, E.in from #9:0 ++ # |@RID|out_ ++ 0 |#9:0|#9:1 ++ *I would have expected the traversal to return all three vertices. Why is that not the case? * 6. traverse * from #9:0 +++ # |@RID|out_|in_ +++ 0 |#9:0|#9:1|null 1 |#9:1|#9:2|#9:0 2 |#9:2|null|#9:1 +++ Thank you for your help! - Jon -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [orientdb] Re: [Java API] Indexing properties and then retrieve using Indexing.
Hi Gerald, GraphAPI uses that convention since long time. If you're interested to this feature, can you open a new issue? Lvc@ On 18 July 2014 17:28, Gerard Solé gerard.sole.castel...@gmail.com wrote: Hi again! I've realised that I cannot use a different index name. If my *class *is *A3User* my index name must be *A3User.id* it can't have a different name as (A3UserIdx), beacuse the internal funcion uses the dot as a separator to obtain the classname and then call de DB to get that class. There are other ways to do this? Thanks in advanced! Gerard. El divendres 18 de juliol de 2014 16:39:45 UTC+2, Gerard Solé va escriure: Hi, I'm trying to index some properties of a subclass of a Vertex (from now, A3User). To create the index I call the following methods: user.createIndex(A3UserIdx.id, OClass.INDEX_TYPE.UNIQUE_HASH_INDEX, User.ID); user.createIndex(A3UserIdx.email, OClass.INDEX_TYPE.UNIQUE_HASH_INDEX, User.EMAIL); Basically, I set has UNIQUE the ID and EMAIL of a user. I saw that passing multiple properties on a unique type index requires that all of that properties need to be unique at the same time, so repeating an id or an email, but not both of them it's count as Unique. Then, I want to retrieve a node from that index, and as I know that the ID or the EMAIL will be unique, I want to call the index to give me a single A3User or at least a list of A3Users which should only be one object. To call this Index I'm trying to use two different functions, both of them return null, and I'm not finding any solution to this problem, so I don't know exactly what I'm doing it wrong. (In OrientDB studio the index seems to be properly created). In studio it is written as: http://i.imgur.com/LGhcxfj.png Methods that return null: String *idxProp *= userId.contains(@)? A3UserIdx.id : A3UserIdx.email; IndexVertex idxV = graph.getIndex(*idxProp*, Vertex.class); graph.getVertices(*idxProp*, userId) -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [orientdb] Re: OrientDB and Grails
Luca, I did some research on this exact choice for OrientDB and can summarise as follows: 1. JavaCC seems to be quite established and there's a rather complete SQL parser written for it (originating from IBM and Informix, passing to Akiban and now part of FoundationDB) https://github.com/FoundationDB/sql-parser - it could be a solid starting point 2. JavaCC seems to lack documentation so for people unfamiliar with writing parsers it could be very difficult 3. ANTLR is very modern, has many nice features and there's a comprehensive book from the author that explains many aspects of writing parsers. 4. An ANTLR parser was started for OrientDB already so was also a good starting point. In my attempt I used ANTLR (and Jonathan Sorel's starting point) but just was not able to complete the task. Ultimately, I'm a pragmatist and have concluded that actually the underlying parser library doesn't matter. I couldn't find any technical pro or con other than my opinion that ANTLR seems a bit cleaner and easier to understand. So, if you hire a parser expert then probably using the IBM/Informix/Akiban/FoundationDB parser code as a starting point will get the job done faster. If you hire someone less familiar with parsers then ANTLR will probably be easier and will likely be something the Open Source community can manage better, Just my thoughts, I hope they help in your evaluation. Best, Emrul On Friday, August 8, 2014 9:39:27 AM UTC+1, Lvc@ wrote: Hi Emrul, The total rewriting of SQL parser has been scheduled for 2.1. We're taking the decision about JavaCC or ANTLR. Pros and Cons of both. Anybody has an opinion on both? Lvc@ On 8 August 2014 01:34, Emrul Islam em...@emrul.com javascript: wrote: Hi Fidel, I had done some work to write a GORM plugin for OrientDB that would allow Grails to directly persist domain objects into OrientDB. However, I had to pause the effort while I waited for a better query API (instead of constructing an SQL string I wanted to programmatically express a query). I shifted my attention to the ANTLR Parser effort but ran out of time. So I have two choices: either finish the ANTLR parser for OrientDB and then finish the Grails plugin or work on constructing an SQL string for queries. I haven't really thought about it in the past few months because I was working on other things. You can still directly call OrientDB just as you can any Java library from Grails, I tested this approach and it worked fine but it means managing your own serialization between OrientDB records and grails domain classes. Good luck in your efforts! On Monday, August 4, 2014 5:22:40 PM UTC+1, Fidel Viegas wrote: Hello, everyone! I have been playing around with orientdb and i would like to put together a small application using grails and was wondering if anyone has worked with grails and orientdb that would like to share his experience. Is there any driver for grails ou there? How could one integrate the java driver? I look forward to hearing from those that have some advice with regards to this combo. Thanks in advance! Best Regards, Fidel H Viegas -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-databa...@googlegroups.com javascript:. For more options, visit https://groups.google.com/d/optout. -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [orientdb] Re: OrientDB and Grails
Hi Emrul, Thanks for your feedback. I'll forward it to the guy ;-) Lvc@ On 9 August 2014 17:25, Emrul Islam em...@emrul.com wrote: Luca, I did some research on this exact choice for OrientDB and can summarise as follows: 1. JavaCC seems to be quite established and there's a rather complete SQL parser written for it (originating from IBM and Informix, passing to Akiban and now part of FoundationDB) https://github.com/FoundationDB/sql-parser - it could be a solid starting point 2. JavaCC seems to lack documentation so for people unfamiliar with writing parsers it could be very difficult 3. ANTLR is very modern, has many nice features and there's a comprehensive book from the author that explains many aspects of writing parsers. 4. An ANTLR parser was started for OrientDB already so was also a good starting point. In my attempt I used ANTLR (and Jonathan Sorel's starting point) but just was not able to complete the task. Ultimately, I'm a pragmatist and have concluded that actually the underlying parser library doesn't matter. I couldn't find any technical pro or con other than my opinion that ANTLR seems a bit cleaner and easier to understand. So, if you hire a parser expert then probably using the IBM/Informix/Akiban/FoundationDB parser code as a starting point will get the job done faster. If you hire someone less familiar with parsers then ANTLR will probably be easier and will likely be something the Open Source community can manage better, Just my thoughts, I hope they help in your evaluation. Best, Emrul On Friday, August 8, 2014 9:39:27 AM UTC+1, Lvc@ wrote: Hi Emrul, The total rewriting of SQL parser has been scheduled for 2.1. We're taking the decision about JavaCC or ANTLR. Pros and Cons of both. Anybody has an opinion on both? Lvc@ On 8 August 2014 01:34, Emrul Islam em...@emrul.com wrote: Hi Fidel, I had done some work to write a GORM plugin for OrientDB that would allow Grails to directly persist domain objects into OrientDB. However, I had to pause the effort while I waited for a better query API (instead of constructing an SQL string I wanted to programmatically express a query). I shifted my attention to the ANTLR Parser effort but ran out of time. So I have two choices: either finish the ANTLR parser for OrientDB and then finish the Grails plugin or work on constructing an SQL string for queries. I haven't really thought about it in the past few months because I was working on other things. You can still directly call OrientDB just as you can any Java library from Grails, I tested this approach and it worked fine but it means managing your own serialization between OrientDB records and grails domain classes. Good luck in your efforts! On Monday, August 4, 2014 5:22:40 PM UTC+1, Fidel Viegas wrote: Hello, everyone! I have been playing around with orientdb and i would like to put together a small application using grails and was wondering if anyone has worked with grails and orientdb that would like to share his experience. Is there any driver for grails ou there? How could one integrate the java driver? I look forward to hearing from those that have some advice with regards to this combo. Thanks in advance! Best Regards, Fidel H Viegas -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-databa...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [orientdb] Re: OrientDB and Grails
Hi Luca and Emrul! I am familiar with all three of them: JavaCC, ANTLR (back when it was only PCCTS) and SableCC. I have written a backend for SableCC that generates Python code, that is the one I am more familiar with as I know the internals. JavaCC generates LL(1) parsers, SableCC generates LALR(1) parsers, similar to Yacc, and ANTLR generates LL(K) parsers. I work mostly with SableCC, because I work a lot with Python, and use the backend implemented by me. However, I would suggest going with the newer version of ANTLR and starting, perhaps, with the grammar for Sqlite found here https://github.com/antlr/grammars-v4. SableCC was working on a newer version, supposed to be version 4 that would allow several backends, but the project does not seem to have much activity based on that version. I am still using a modified version of SableCC 3 that has a language to generate the backends. I implemented the Python backend and was interested in implementing the backend for SableCC 4, but I don't really see much activity there. Now, as for ANTLR there seems to be a lot of progress, as we keep seeing versions coming out. Terrence Parr is continuously working on it and there's a lot of support for other languages as well. Emrul, is your project available in any repository you could share? I would be interested in seeing the code, and if I find some time I could probably give you a hand. Regards, Fidel H Viegas On Sat, Aug 9, 2014 at 4:52 PM, Luca Garulli l.garu...@gmail.com wrote: Hi Emrul, Thanks for your feedback. I'll forward it to the guy ;-) Lvc@ On 9 August 2014 17:25, Emrul Islam em...@emrul.com wrote: Luca, I did some research on this exact choice for OrientDB and can summarise as follows: 1. JavaCC seems to be quite established and there's a rather complete SQL parser written for it (originating from IBM and Informix, passing to Akiban and now part of FoundationDB) https://github.com/FoundationDB/sql-parser - it could be a solid starting point 2. JavaCC seems to lack documentation so for people unfamiliar with writing parsers it could be very difficult 3. ANTLR is very modern, has many nice features and there's a comprehensive book from the author that explains many aspects of writing parsers. 4. An ANTLR parser was started for OrientDB already so was also a good starting point. In my attempt I used ANTLR (and Jonathan Sorel's starting point) but just was not able to complete the task. Ultimately, I'm a pragmatist and have concluded that actually the underlying parser library doesn't matter. I couldn't find any technical pro or con other than my opinion that ANTLR seems a bit cleaner and easier to understand. So, if you hire a parser expert then probably using the IBM/Informix/Akiban/FoundationDB parser code as a starting point will get the job done faster. If you hire someone less familiar with parsers then ANTLR will probably be easier and will likely be something the Open Source community can manage better, Just my thoughts, I hope they help in your evaluation. Best, Emrul On Friday, August 8, 2014 9:39:27 AM UTC+1, Lvc@ wrote: Hi Emrul, The total rewriting of SQL parser has been scheduled for 2.1. We're taking the decision about JavaCC or ANTLR. Pros and Cons of both. Anybody has an opinion on both? Lvc@ On 8 August 2014 01:34, Emrul Islam em...@emrul.com wrote: Hi Fidel, I had done some work to write a GORM plugin for OrientDB that would allow Grails to directly persist domain objects into OrientDB. However, I had to pause the effort while I waited for a better query API (instead of constructing an SQL string I wanted to programmatically express a query). I shifted my attention to the ANTLR Parser effort but ran out of time. So I have two choices: either finish the ANTLR parser for OrientDB and then finish the Grails plugin or work on constructing an SQL string for queries. I haven't really thought about it in the past few months because I was working on other things. You can still directly call OrientDB just as you can any Java library from Grails, I tested this approach and it worked fine but it means managing your own serialization between OrientDB records and grails domain classes. Good luck in your efforts! On Monday, August 4, 2014 5:22:40 PM UTC+1, Fidel Viegas wrote: Hello, everyone! I have been playing around with orientdb and i would like to put together a small application using grails and was wondering if anyone has worked with grails and orientdb that would like to share his experience. Is there any driver for grails ou there? How could one integrate the java driver? I look forward to hearing from those that have some advice with regards to this combo. Thanks in advance! Best Regards, Fidel H Viegas -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an
[orientdb] Re: Question on traverse with graph DB
After looking at the results of select from V and seeing out_ and in_ instead of out and in I tried this: traverse V.out_, E.in_ from #9:0 and it did traverse all the outgoing vertices. However, all the documentation that I have read refers to V.out, E.in. What have I missed? Again I'm using 1.7.7 community Thanks! On Saturday, August 9, 2014 9:09:04 AM UTC-4, Jon Fields wrote: Hi, I just learned about and started experimenting with OrientDB (1.7.7 community) a few days ago. I am very impressed. I apologize if this is a newbie question, however, I am having trouble understanding traverse with a graph DB. Steps: 1. Create a new plocal graph database 2. create three vertices: #9:0, #9:1, #9:2 just using create vertex V 3. create three edges: 1. create edge E from #9:0 to #9:1 2. create edge E from #9:1 to #9:2 3. create edge E from #9:2 to #9:3 4. select from V: +++ # |@RID|out_|in_ +++ 0 |#9:0|#9:1|null 1 |#9:1|#9:2|#9:0 2 |#9:2|null|#9:1 +++ 5. traverse V.out, E.in from #9:0 ++ # |@RID|out_ ++ 0 |#9:0|#9:1 ++ *I would have expected the traversal to return all three vertices. Why is that not the case? * 6. traverse * from #9:0 +++ # |@RID|out_|in_ +++ 0 |#9:0|#9:1|null 1 |#9:1|#9:2|#9:0 2 |#9:2|null|#9:1 +++ Thank you for your help! - Jon -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [orientdb] Re: OrientDB and Grails
I visited ANTLR website once again, and just noticed that Hibernate's HQL language was implemented in ANTLR (http://www.antlr.org/about.html) Perhaps that would be a good choice, I guess. Regards, Fidel H Viegas On Sat, Aug 9, 2014 at 5:37 PM, Fidel H Viegas fidel.vie...@gmail.com wrote: Hi Luca and Emrul! I am familiar with all three of them: JavaCC, ANTLR (back when it was only PCCTS) and SableCC. I have written a backend for SableCC that generates Python code, that is the one I am more familiar with as I know the internals. JavaCC generates LL(1) parsers, SableCC generates LALR(1) parsers, similar to Yacc, and ANTLR generates LL(K) parsers. I work mostly with SableCC, because I work a lot with Python, and use the backend implemented by me. However, I would suggest going with the newer version of ANTLR and starting, perhaps, with the grammar for Sqlite found here https://github.com/antlr/grammars-v4. SableCC was working on a newer version, supposed to be version 4 that would allow several backends, but the project does not seem to have much activity based on that version. I am still using a modified version of SableCC 3 that has a language to generate the backends. I implemented the Python backend and was interested in implementing the backend for SableCC 4, but I don't really see much activity there. Now, as for ANTLR there seems to be a lot of progress, as we keep seeing versions coming out. Terrence Parr is continuously working on it and there's a lot of support for other languages as well. Emrul, is your project available in any repository you could share? I would be interested in seeing the code, and if I find some time I could probably give you a hand. Regards, Fidel H Viegas On Sat, Aug 9, 2014 at 4:52 PM, Luca Garulli l.garu...@gmail.com wrote: Hi Emrul, Thanks for your feedback. I'll forward it to the guy ;-) Lvc@ On 9 August 2014 17:25, Emrul Islam em...@emrul.com wrote: Luca, I did some research on this exact choice for OrientDB and can summarise as follows: 1. JavaCC seems to be quite established and there's a rather complete SQL parser written for it (originating from IBM and Informix, passing to Akiban and now part of FoundationDB) https://github.com/FoundationDB/sql-parser - it could be a solid starting point 2. JavaCC seems to lack documentation so for people unfamiliar with writing parsers it could be very difficult 3. ANTLR is very modern, has many nice features and there's a comprehensive book from the author that explains many aspects of writing parsers. 4. An ANTLR parser was started for OrientDB already so was also a good starting point. In my attempt I used ANTLR (and Jonathan Sorel's starting point) but just was not able to complete the task. Ultimately, I'm a pragmatist and have concluded that actually the underlying parser library doesn't matter. I couldn't find any technical pro or con other than my opinion that ANTLR seems a bit cleaner and easier to understand. So, if you hire a parser expert then probably using the IBM/Informix/Akiban/FoundationDB parser code as a starting point will get the job done faster. If you hire someone less familiar with parsers then ANTLR will probably be easier and will likely be something the Open Source community can manage better, Just my thoughts, I hope they help in your evaluation. Best, Emrul On Friday, August 8, 2014 9:39:27 AM UTC+1, Lvc@ wrote: Hi Emrul, The total rewriting of SQL parser has been scheduled for 2.1. We're taking the decision about JavaCC or ANTLR. Pros and Cons of both. Anybody has an opinion on both? Lvc@ On 8 August 2014 01:34, Emrul Islam em...@emrul.com wrote: Hi Fidel, I had done some work to write a GORM plugin for OrientDB that would allow Grails to directly persist domain objects into OrientDB. However, I had to pause the effort while I waited for a better query API (instead of constructing an SQL string I wanted to programmatically express a query). I shifted my attention to the ANTLR Parser effort but ran out of time. So I have two choices: either finish the ANTLR parser for OrientDB and then finish the Grails plugin or work on constructing an SQL string for queries. I haven't really thought about it in the past few months because I was working on other things. You can still directly call OrientDB just as you can any Java library from Grails, I tested this approach and it worked fine but it means managing your own serialization between OrientDB records and grails domain classes. Good luck in your efforts! On Monday, August 4, 2014 5:22:40 PM UTC+1, Fidel Viegas wrote: Hello, everyone! I have been playing around with orientdb and i would like to put together a small application using grails and was wondering if anyone has worked with grails and orientdb that would like to share his experience. Is there any driver for grails ou there? How could one integrate the java driver? I
Re: [orientdb] Re: OrientDB and Grails
I've used antlr 3 4, and the changes in 4 make it extremely easy to use, within the scope of parsing grammars. The only benefit to javacc that I'm aware of is the lack of a runtime dependency, but I believe the flexibility during grammar development more than makes up for it since the antlr license is friendly. -- Curtis Ruck Anytime: 210-857-1126 On Sat, Aug 9, 2014 at 12:52 PM, Fidel H Viegas fidel.vie...@gmail.com wrote: I visited ANTLR website once again, and just noticed that Hibernate's HQL language was implemented in ANTLR (http://www.antlr.org/about.html) Perhaps that would be a good choice, I guess. Regards, Fidel H Viegas On Sat, Aug 9, 2014 at 5:37 PM, Fidel H Viegas fidel.vie...@gmail.com wrote: Hi Luca and Emrul! I am familiar with all three of them: JavaCC, ANTLR (back when it was only PCCTS) and SableCC. I have written a backend for SableCC that generates Python code, that is the one I am more familiar with as I know the internals. JavaCC generates LL(1) parsers, SableCC generates LALR(1) parsers, similar to Yacc, and ANTLR generates LL(K) parsers. I work mostly with SableCC, because I work a lot with Python, and use the backend implemented by me. However, I would suggest going with the newer version of ANTLR and starting, perhaps, with the grammar for Sqlite found here https://github.com/antlr/grammars-v4. SableCC was working on a newer version, supposed to be version 4 that would allow several backends, but the project does not seem to have much activity based on that version. I am still using a modified version of SableCC 3 that has a language to generate the backends. I implemented the Python backend and was interested in implementing the backend for SableCC 4, but I don't really see much activity there. Now, as for ANTLR there seems to be a lot of progress, as we keep seeing versions coming out. Terrence Parr is continuously working on it and there's a lot of support for other languages as well. Emrul, is your project available in any repository you could share? I would be interested in seeing the code, and if I find some time I could probably give you a hand. Regards, Fidel H Viegas On Sat, Aug 9, 2014 at 4:52 PM, Luca Garulli l.garu...@gmail.com wrote: Hi Emrul, Thanks for your feedback. I'll forward it to the guy ;-) Lvc@ On 9 August 2014 17:25, Emrul Islam em...@emrul.com wrote: Luca, I did some research on this exact choice for OrientDB and can summarise as follows: 1. JavaCC seems to be quite established and there's a rather complete SQL parser written for it (originating from IBM and Informix, passing to Akiban and now part of FoundationDB) https://github.com/FoundationDB/sql-parser - it could be a solid starting point 2. JavaCC seems to lack documentation so for people unfamiliar with writing parsers it could be very difficult 3. ANTLR is very modern, has many nice features and there's a comprehensive book from the author that explains many aspects of writing parsers. 4. An ANTLR parser was started for OrientDB already so was also a good starting point. In my attempt I used ANTLR (and Jonathan Sorel's starting point) but just was not able to complete the task. Ultimately, I'm a pragmatist and have concluded that actually the underlying parser library doesn't matter. I couldn't find any technical pro or con other than my opinion that ANTLR seems a bit cleaner and easier to understand. So, if you hire a parser expert then probably using the IBM/Informix/Akiban/FoundationDB parser code as a starting point will get the job done faster. If you hire someone less familiar with parsers then ANTLR will probably be easier and will likely be something the Open Source community can manage better, Just my thoughts, I hope they help in your evaluation. Best, Emrul On Friday, August 8, 2014 9:39:27 AM UTC+1, Lvc@ wrote: Hi Emrul, The total rewriting of SQL parser has been scheduled for 2.1. We're taking the decision about JavaCC or ANTLR. Pros and Cons of both. Anybody has an opinion on both? Lvc@ On 8 August 2014 01:34, Emrul Islam em...@emrul.com wrote: Hi Fidel, I had done some work to write a GORM plugin for OrientDB that would allow Grails to directly persist domain objects into OrientDB. However, I had to pause the effort while I waited for a better query API (instead of constructing an SQL string I wanted to programmatically express a query). I shifted my attention to the ANTLR Parser effort but ran out of time. So I have two choices: either finish the ANTLR parser for OrientDB and then finish the Grails plugin or work on constructing an SQL string for queries. I haven't really thought about it in the past few months because I was working on other things. You can still directly call OrientDB just as you can any Java library from Grails, I tested this approach and it worked fine but it means managing your own serialization between OrientDB records and
Re: [orientdb] Re: OrientDB and Grails
On Sat, Aug 9, 2014 at 6:28 PM, Curtis Ruck curtis.r...@gmail.com wrote: I've used antlr 3 4, and the changes in 4 make it extremely easy to use, within the scope of parsing grammars. The only benefit to javacc that I'm aware of is the lack of a runtime dependency, but I believe the flexibility during grammar development more than makes up for it since the antlr license is friendly. I haven't played with ANTLR in a while, but I have used antlr 3 last year. JavaCC on its own without JJTree is not as easy as SableCC or ANTLR with regards to tree traversals. I tried to use it in a project a couple of years ago, but dumped it over SableCC due to simplicity. It was faster than SableCC, though. What are you guys using at the moment? Regards, Fidel H Viegas -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[orientdb] Link to ODocument corrupted by DB [issue 2660]
Initially the db saves the contents of tyrionDoc properly after the
fromJSON method. However, the query returns a document with modified
values in the contact field. Specifically, the contact value included the
rid of another document, and is replaced by the values of the document but
no longer contains the rid of the document. It is not clear what is trigger
the data modification.
import com.orientechnologies.orient.core.record.impl.ODocument;
import com.orientechnologies.orient.core.sql.query.OSQLSynchQuery;
import com.orientechnologies.orient.core.db.document.ODatabaseDocumentTx;
import java.util.List;
class InnerDoc {
public static void main(String[] args) {
ODatabaseDocumentTx db = new ODatabaseDocumentTx(
remote:localhost/amazingorient);
db.open(admin, admin);
ODocument jaimeDoc = new ODocument(PersonTest);
jaimeDoc.field(name, jaime);
jaimeDoc.save();
ODocument tyrionDoc = new ODocument(PersonTest);
tyrionDoc
.fromJSON({\@type\:\d\,\name\:\tyrion\,\emergency_contact\:[{\relationship\:\brother\,\contact\:
+ jaimeDoc.toJSON() + }]});
tyrionDoc.save();
System.out.println(db.load(tyrionDoc.getIdentity()).toJSON());
ListODocument result = db.query(
new OSQLSynchQueryODocument(select from +
tyrionDoc.getIdentity()));
System.out.println(result.get(0).toJSON());
db.close();
}
}
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[orientdb] OrientDB as database for Analytics?
Luca, We were considering OrientDb for analytical reports for one of our projects. Specifically, the use of window functions, quite common in high-end SQL systems. Eventually we decided to use PostgreSQL, as OrientDB did not have them. With Java 8 streams and lambda, however, one may implement this easily, without support from OrientDb? Are you also considering cubes, dimensions, MDX and other BI tools of the trade to implement in OrientDb? Maybe you can just provide an OrientDb backend for the Mondrian OLAP server by Pentaho nstead... -- --- You received this message because you are subscribed to the Google Groups OrientDB group. To unsubscribe from this group and stop receiving emails from it, send an email to orient-database+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
