Monero Stack Exchange
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Questions tagged [lmdb]

LMDB is an extraordinarily fast, memory-efficient database used by Monero. Its author Howard Chu is now a contributing member of the Monero development team.

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Why did Monero choose LMDB over alternative database types?

Did the Monero development find LMDB architect and developer Howard Chu because of its interest in LMDB? Or was LMDB introduced to the Monero development team because of Howard Chu's interest in Monero? Why did Monero choose LMDB over alternatives…
animal instinct
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How many transactions per second can the Monero network handle?

How many transactions per second can the Monero network (theoretically) handle? Did recent LMDB optimizations improve the speed that CPUs can confirm transactions? Is the current limiting factor CPU confirmation time, bandwidth of Monero nodes or…
Logan
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Why does `monerod` on Raspberry Pi 3 with a copied LMDB not catch up with new blocks?

I have both a macOS system and a Raspberry Pi 3 on the same home network. Both are having Monero release 0.10.1.0 installed. I stopped the daemon on macOS, and then copied the entire .bitmonero directory from macOS to the Raspberry Pi 3 (running…
dpzz
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How can one query the blockchain's database?

I realize that LMDB is very different from your typical SQL database, but is there a query language, or scripting language interface, that can be used to query the blockchain's database? I am aware of this question on displaying the output histogram…
dpzz
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Is Monero the first cryptocurrency to use Confidential Transactions (RingCT), 0MQ, and LMDB?

I assume these technologies exist in other usages, but are we the first coin to implement them?
user4
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Blockchain database file size variance by Operating System

I have a full node on both an Ubuntu 16.04 LTS and a Windows 10 device. Why is the database file containing blockchain a different size on each OS?
animal instinct
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Is the Monero blockchain database portable between 32 and 64 bit architectures, and little/big endian architectures?

Monero uses LMDB for its database. Various data is saved in this database, including integers, such as the difficulty for a given block. LMDB is type agnostic, so does not any particular processing on integers and other types. Is this database…
user36303
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Are the LMDB files cross-platform compatible?

I would like to know if the LMDB files are cross-platform compatible, more specifically between macOS and Linux. I am trying to import a raw blockchain (that I exported yesterday on macOS) onto a Raspberry Pi 3. However, judging from the current…
dpzz
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Why would you need multiple daemons using one LMDB database?

From the release notes of the latest monero 0.10.2 version: added support for multiple daemons using the same LMDB database What sensible use case should that cover? From my understanding, LMDB databases are meant to be used locally, so for what…
janowitz
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LMDB conversion vs downloading from scratch

What are the speed and security differences between a pre LMDB (0.8.6) to LMDB (0.9.4) conversion vs syncing the blockchain from scratch? I have a Linux Ubuntu desktop with 8GB RAM a 512 GM SSD and a blockchain that has not been updated since…
J Dog
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What does it mean when the Monero daemon says "LMDB Mapsize increased"?

I had an old daemon open and it was giving me the various SYNCHRONIZED OK messages that I was used to. Suddenly it said "LMDB Mapsize increased. Old: 13312MiB, New: 14336MiB". What does this mean?
user4
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What is the best way to pop the top block from the monero blockchain and fix a bad "unknown top block" error in the sync data process?

It appears whilst syncing the blockchain the computer halted resulting in a bad block at the top of the chain. After restarting no more blocks are being added and just repeated errors. There is probably a way to pop the top blocks off the stack of…
JVP
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bitmonerod data-dir in a virtualbox shared folder

I'm trying to run bitmonerod in a VirtualBox VM with --data-dir pointing to a directory in a shared folder from the host system. I get this error: If I do the same in the host system, using the same directory in the shared folder, it works. It…
villabacho
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blockchain_import fails, "Transaction has too many dirty pages - transaction too big"

I'm trying to set up a node and import the raw blockchain. OS is Whonix with 2GB RAM and plenty of free disk space hosted on Win7 ENT. user@host:~/Desktop/monero$ ./blockchain_import --input-file blockchain.raw 2016-Aug-30 08:49:32.647152…
avnr
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Moving LMDB from Laptop to SBC?

I have a synced Database on my Laptop running W10, but I want run monerod on my Odroid C1 running debian linux. Is it possible to move the database from the Laptop to the SBC
user2025362
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